SEI
STOCKHOLM
ENVIRONMENT
INSTITUTE
Boston Center, Tellus Institute
11 Arlington Street, Boston, MA, 02116 USA
A Guide to Environmental Analysis
For Energy Planners
Prepared By:
Michael Lazarus and David Von Hippel
with
David Hill and Robert Margolis
Stockholm Environment Institute--Boston
December 1995
Table of Contents
1. INTRODUCTION............................................................................................................................................ 1
1.1 KEY ISSUES AND THE DESIGN OF THE GUIDE ................................................................................................... 2
1.2 CHALLENGES AND CONCERNS IN QUANTITATIVE ANALYSIS ............................................................................ 7
2. MAJOR ENVIRONMENTAL PROBLEMS ASSOCIATED WITH ENERGY ACTIVITIES .................. 11
2.1 INTRODUCTION ........................................................................................................................................... 11
2.2 GLOBAL ISSUES........................................................................................................................................... 13
2.3 REGIONAL ISSUES........................................................................................................................................ 23
2.4 LOCAL ISSUES ............................................................................................................................................. 34
3. DESCRIPTION OF MAJOR ENVIRONMENTAL EFFECTS CATEGORIES......................................... 43
3.1 INTRODUCTION ........................................................................................................................................... 43
3.2 AIR EMISSIONS ........................................................................................................................................... 48
3.3 WATER EFFLUENTS ..................................................................................................................................... 61
3.4 SOLID WASTES ........................................................................................................................................... 64
3.5 OCCUPATIONAL HEALTH AND SAFETY EFFECTS ............................................................................................ 65
3.6 OTHER EFFECTS .......................................................................................................................................... 65
4. ENVIRONMENTAL LOADING DATA: SOURCES, ESTIMATION, AND UNCERTAINTY ................ 67
4.1 INTRODUCTION ........................................................................................................................................... 67
4.2 EMISSION FACTORS: WHAT THEY ARE AND WHERE THEY COME FROM............................................................ 67
4.3 THE CAUSE-AND-EFFECT RELATIONSHIP IN EMISSION FACTORS .................................................................... 71
4.4 DETERMINING THE APPROPRIATE UNITS FOR EMISSION FACTORS .................................................................. 72
4.5 MEASUREMENT AND ESTIMATION OF EMISSION AND IMPACT FACTORS .......................................................... 75
4.6 DETERMINING THE APPROPRIATE EMISSION FACTORS TO USE ......................................................................... 83
4.7 UNCERTAINTY, ERRORS AND LIMITS OF APPLICABILITY................................................................................ 87
4.8 CATEGORIES OF EMISSION FACTORS PARTICULARLY SENSITIVE TO LOCAL CONDITIONS.................................... 88
4.9 MAJOR SOURCES AND TYPES OF EMISSION FACTORS DATA.............................................................................. 92
5. DEVELOPING LOADINGS INVENTORIES AND PROJECTIONS FOR THE ENERGY SECTOR..... 94
5.1 INTRODUCTION ........................................................................................................................................... 95
5.2 LEAP AND EDB......................................................................................................................................... 97
5.3 STEP-BY-STEP GUIDE TO PERFORMING ENERGY AND ENVIRONMENTAL ANALYSIS ......................................... 98
5.4 A CASE-STUDY APPLICATION OF LEAP AND EDB: COSTA RICA .................................................................108
6. EXTENDING THE ANALYSIS FROM EMISSIONS TO DAMAGE .......................................................117
6.1 INTRODUCTION ..........................................................................................................................................117
6.2 STEPS OF ANALYSIS FROM EMISSION TO IMPACTS ........................................................................................118
6.3 TYPES OF MODELS AND APPROACHES FOR IMPACT ASSESSMENT ..................................................................122
6.4 SOME SIMPLIFIED INDICES AND SELECTED STANDARDS ...............................................................................128
6.5 SUGGESTED RESOURCES FOR ENVIRONMENTAL MODELING..........................................................................130
7. REFERENCES..............................................................................................................................................131
APPENDIX A: ANNOTATED LIST OF LITERATURE REFERENCES USED IN COMPILING THE
ENVIRONMENTAL DATABASE (EDB.........................................................................................................139
APPENDIX B: SUMMARY OF TABLE OF CONTENTS FROM GUIDELINE ON AIR QUALITY
MODELS (USEPA)...........................................................................................................................................163
ACKNOWLEDGMENTS
The authors the Swedish International Development Agency for supporting the development of this Guide.
We would also like to thank Gordon Mackenzie of the UNEP Collaborating Centre for his comments and
encouragement, as well as Charlie Heaps and Evan Hansen who contributed to the development of EDB,
and provided materials for this manual. The concept of this guide was inspired by requests from energy
planners and analysts -- particularly input from Bashiri Mrindoko of the Tanzanian Ministry of Energy and
Minerals -- for a reference guide and background material on a growing area of their interest and
responsibility.
STOCKHOLM ENVIRONMENT INSTITUTE--BOSTON
Tellus Institute
11 Arlington Street
Boston, Massachusetts, 02116-3411 USA
Telephone: 617-266-8090
Telefax: 617-266-8303
Email: [email protected]
Internet: http://www.tellus.org
Introduction
1
1. Introduction
The incorporation of environmental considerations has become an important new area for energy
planners. Energy use and production can be major sources of serious environmental impacts. These
impacts, in turn, can threaten the overall social and economic development objectives that energy use is
thought to promote. Examples of such dilemmas abound. At the regional and global levels, fossil fuel
consumption leads to acid rain and, most likely, to global warming; both phenomena could disrupt natural
systems and economic productivity. At the local level, continued reliance on traditional biomass fuels, in
many developing countries, can place added stress on woodlands and farmlands, further contributing to soil
erosion and habitat loss, and can lead to high levels of indoor air pollution.
In many countries, success in resolving energy-environmental questions is critical. Rapid changes
are occurring in both rural and urban areas that will affect generations to come. Land clearing for
agriculture and energy have local impacts and potential global climate impacts. The rapid expansion of
urban areas is changing energy use patterns, as more people enter the cash economy and commercial fuels
(electricity, petroleum products, etc.) become options for displacing their use of traditional fuel use (wood,
charcoal, crop residues, etc.). The demand for energy services such as space cooling and transportation
tends to increase very rapidly with industrialization and rising incomes. Such so-called energy transitions,
when they occur, will have significant effects on air, water, and land, locally and globally. At present,
there are great opportunities for directing energy use and production patterns toward those that, recognizing
environmental externalities, will help to minimize long-term economic and social costs.
To this end, many countries are currently building energy and environmental planning capacity.
These institutions are generally relatively new and in need of important resources: training, experience, and
useful methods adapted to local conditions. Environmental analyses have tended to be few, and prepared
on an ad-hoc basis as needed for project approval -- often at the behest of donor agencies. The lack of
local studies and data can impose serious constraints on planning, as can the near-term and growth-oriented
focus of developing economies. Applicable planning methods must consider these constraints.
Computerized decision support systems can provide useful assistance in the analysis of available
information, the projection of future conditions, and the evaluation of alternative scenarios. The use of
these systems can help countries advance toward the goal of implementing useful analytic methods for
energy and environment planning. One such tool is the Long-Range Energy Alternatives planning system
(LEAP), used by energy ministries and researchers in over 30 countries worldwide. With support from the
United Nations Environment Programme (UNEP) and the Swedish International Development Agency
(SIDA), SEI-B expanded LEAP to enable more integrated energy-environmental analysis. The major
product of this effort, the Environmental Data Base (EDB), contains an extensive collection of emission
and direct impact coefficients for a wide range of energy producing, consuming, and conversion processes
and technologies. EDB can also incorporate local data, if available, on emissions and direct impacts of
energy processes. The analyst can then use EDB data with LEAP to estimate the comparative
environmental loadings associated with a range of energy scenarios.
The expansion of energy scenario analysis to incorporate environmental considerations raises a
number of important questions and challenges, ranging from the choice of which factors to include in the
analysis to the evaluation of results across scenarios and categories of environmental impact. At the outset,
it is crucial to emphasize that integrated energy-environmental analysis is still a relatively new and evolving
field, particularly when compared to energy analysis alone. Most LEAP users, for instance -- a group
comprised largely of energy planners, engineers, and economists -- are familiar with the challenges posed
2
A Guide to Environmental Analysis For Energy Planners
by limited data and understanding of the factors and relationships (price, income, saturation, politics, and
others) affecting energy use. On the model development side, assembling a set of estimates and
assumptions regarding physical and direct cost impacts of energy technologies and policies may take
considerable effort, but the methods are relatively straightforward. On the model output side, economic
indicators such cost-benefit ratios and oil import bills, and physical indicators such as energy balance
sheets and cumulative resource depletion are well defined. In contrast, when we turn to environmental
"inputs" and "outputs", we are confronted with a far more complex web of relationships -- from local to
global scales and from human health to ecological issues -- and far less in terms of standard methods and
precise information.
This guide provides a path that leads, one might say, both into and out of the woods. We present
some of the complexities and uncertainties of energy-environment relationships, and follow with
information and guidance for conducting integrated analyses. Together, LEAP and EDB provide a
relatively simple and flexible quantitative framework for approaching many of the important environmental
and economic consequences of energy strategies. While this flexibility enables the planner to construct a
model and use data applicable to local concerns, it also requires the background and knowledge to do so in
an appropriate manner. Furthermore, the quantitative nature of the analysis conducted with such a model
should not diminish the importance of issues that are non-quantifiable or consideration of topics for which
data or relationships are highly uncertain.
The art of judicious simplification becomes essential to avoiding the potentially overwhelming
diversity of approaches and issues that may be of concern to a planning agency. Each environmental
concern, from the impacts of cooking fuels and practices on human health to the ecological consequences of
exploiting biomass, hydro, or surface coal resources, may appear worthy of detailed and localized study.
These studies should be initiated where appropriate, but the absence of such studies should not preclude the
initial incorporation of environmental concerns in energy planning.
1.1 Key Issues and the Design of the Guide
Given these challenges and concerns, we initially conceived this guide as a companion manual to
assist users of LEAP and EDB. Many users requested additional assistance in incorporating environmental
parameters into their energy analyses. LEAP/EDB users are typically energy planners with limited, if any,
previous exposure to environmental science, and several have asked for more background on the nature of
various pollutants, from their sources to their pathways of impact. In response, Section 2 provides a
general overview of the major global, regional, and local environment issues related to energy use, and
Section 3 describes the major pollutant and impact categories as used in EDB.
In conducting an integrated energy-environment analysis, one must establish several sets of
boundaries. One of these sets defines which environmental concerns (indoor air quality, land degradation,
global climate change, etc.) and related parameters (toxic hydrocarbon emissions, cleared land, greenhouse
gas emissions, etc.) to investigate and consider. Such a list is ideally based upon a thorough assessment of
national and local environmental concerns and priorities. Comparative environmental analysis can play an
important role in determining these priorities, and in turn, can help to orient the emphasis of integrated
energy-environmental analyses1. For example, a number of developing country energy studies and
programs of the 1970s and 1980s were based on the notion that deforestation and desertification were
1 Comparative environmental assessment seeks to evaluate the relative risks posed by the multitude of environmental
problems using a combination of risk analysis and expert judgment. See Unfinished Business: A Comparative Assessment of
Environmental Problems: Overview Report, U.S. Environmental Protection Agency, Office of Policy Analysis, February 1987.
Introduction
3
rapidly expanding largely as the result of the demand for woodfuels. In a number of cases, however, other
causal factors -- land clearing for agriculture, timber exports, and other non-energy factors -- have been as
important, or more so, in causing these problems. Comparative risk analyses or other more simpler studies,
such as national reports to the 1992 Rio UNCED Conference, or National Environmental Action Plans, can
provide an important starting point for outlining the important energy-environment issues that should be
emphasized2.
It is also necessary to define a set of boundaries around those effects of the energy system that will
be considered. For instance, a new coal-fired electric facility will require materials and energy for plant
construction, will require disposal of ashes and/or scrubber wastes during plant operation, and will require
transport of coal from the mine. Disposal of waste will involve additional transportation to and from the
disposal sites. One can go further down the chain of required events and measure, for example, the impacts
of manufacturing the additional vehicles required for waste disposal. Obviously, these sorts of analyses -often referred to as life cycle, full fuel cycle, or fuel chain analyses -- can go on ad infinitum (that is,
indefinitely). To deal with similar types of interlinkages in the full economy, economists have developed
input-output models. While there are no similarly well-developed methods or models for full fuel cycle
analysis, many attempts have been made to define the most important aspects of individual fuel cycles -for example, alcohol from biomass, or electricity from coal -- that should be considered. LEAP itself
embodies a fuel cycle approach, and has recently been expanded to enable straightforward fuel cycle
environmental comparisons as part of a UNEP-sponsored project.
In principle, when evaluating fuel choices such as gasoline versus ethanol for vehicle
transportation, it is important to consider the primary effects of each major element of the fuel chain, as
illustrated in Figure 1.1 below for gasoline. Some “upstream” fuel cycle impacts may occur outside the
region of concern. For instance, oil may be imported and the impacts of oil production thus do not occur
locally. It is then up to existing environmental laws or to the analyst’s judgment as to whether these
impacts should be considered. Secondary impacts, such as the emissions from production of electricity or
from the manufacture of steel used at the refinery, vary significantly depending on fuel and technology
options considered, but are generally much less important -- and much more difficult to quantify -- than the
primary impacts3.
Section 4 deals with issues related to the development and use of pollutant loading factors (see
Table 1.3 for a definition of this term), and in particular, with the origins of the over 2000 coefficients for
air, water, and solid waste emissions, and land use and direct health and safety impacts found in the
Environmental Data Base (EDB). Air pollutant emission factors, the most commonly reported and perhaps
most important of the energy-related loading factors, are developed from laboratory and field tests under
conditions (combustion technologies, ambient conditions, etc.) that may differ significantly from those
under study. Very few of the available and published emission factors are based on measurements done in
developing countries. Most factors are derived from a relatively limited number of studies to date, most
based on measurements in and for OECD countries, most notably the US, under the ambient conditions
(temperature, humidity, etc.), technologies, and operational practices that prevailed where the
measurements were made. In fact, a large number of the published emission factors for fossil fuel
combustion can be traced to a handful of U.S. studies done in the 1980s. We discuss the origins of the
2 Several African countries have prepared National Environmental Action Plans, a concept initiated by the World Bank, for
identifying and prioritizing key environmental issues, focusing on their underlying causes, and developing a plan for addressing
them. See Falloux, F., Talbot, L., Larson, J. “Progress and Next Steps for National Environmental Action Plans in Africa”,
World Bank Africa Technical Department, June 1991.
3 For more information on fuel cycle analyses, see DeLuchi, 1991.
4
A Guide to Environmental Analysis For Energy Planners
emission factor data found in EDB, provide some guidance for their use, and suggest where to seek
additional data -- or perform more detailed analysis -- if needed. Appendix A contains an annotated
bibliography of the over 70 references used to develop EDB data.
Table 1.1:
Example of Possible Environmental Impacts for the Gasoline Fuel Cycle
Activity
Locate oil deposit
ê
Drill oil well
ê
Extract crude oil
ê
Transport crude oil to refinery
ê
Refine oil into gasoline
ê
Transport gasoline to filling station
ê
Fill cars with fuel
ê
Operate vehicle
Possible Environmental Concern
(road building in pristine areas)
(construction, land use, accidents)
(accidents, spills, gas flaring)
(accidents, spills)
(air emissions, solid and hazardous wastes)
(accidents, spills)
(leakage from storage, evaporative emissions)
(evaporative and combustion emissions)
In general, estimates for some of the loading categories other than air pollutants, such as on-site
health and safety impacts or land use and degradation, tend to be more highly site-specific, more difficult to
generalize to facilities in use in different countries or regions, and less linearly related to the quantity of
energy produced or consumed. Thus, only a small fraction of the coefficients in EDB refer to these types
of effects The user can, however, add this type of information to EDB if it is available and relevant to a
particular study.
Section 5 of this Guide presents an overview of the application of LEAP/EDB to the
environmental analysis of energy scenarios, with specific examples demonstrating how LEAP and EDB can
be used. The integrated energy-environment approach that underlies both this manual and the design of
LEAP and EDB is described in Box 1.1 below. In keeping with the considerable uncertainties in data and
scientific understanding in the environmental field, the LEAP/EDB approach to environmental analysis is
simplified and limited, yet still powerful. Because it provides an international database of emission factors,
EDB provides planners with a "jump-start" in collection of environmental data. In the absence of local
data, default EDB data can provide useful initial estimates. When EDB data are linked to specific energy
processes, LEAP can be used to illustrate how different energy strategies could yield different future
outcomes in terms of emissions and impact indicators.
Introduction
5
BOX 1.1:
Steps in Integrated Energy-Environment Analysis
Three basic principles underlie integrated energy-environment analysis. First, the analysis considers all
fuels and technologies, whether on the supply or demand side, on equal footing. Second, the ultimate goal is the
provision of end-use services and amenities (hot water, lighting, transport, etc.), rather than simply fuels or
electricity, at the least social cost. Finally, the broader analysis seeks to incorporate the economic externalities -most notably environmental and equity impacts -- absent from a traditional cost-benefit analysis based on market
prices alone. The necessary longer-term planning horizon (such as > 10 years), stretches beyond, but not in
isolation from, the short-term issues that often dominate the planning realm.
The following six steps define an idealized process for conducting an integrated energy-environment
analysis, and formulating environmentally-informed energy policy: Note that this process is usually carried out in
an iterative manner, with later steps informing or suggesting modifications to previous steps.
1) Determine Planning Goals: The definition of the planning goals to be met will help to determine the
extent of data that must be collected, the types of scenarios to be run, and the categories of results that will be
needed.
2) Characterize Baseline Energy Situation: This step involves the establishment of a reliable database for
projecting future energy needs, comparing technological alternatives, and evaluating policy impacts. The
characterization prepared may be for a particular project, a regional energy system, or anything level of aggregation
in between. Additional data collection activities may be identified and undertaken.
3) Prepare Baseline Energy Scenarios: In this step a plausible baseline policy-neutral scenario (or set of
baseline scenarios) that reflects "business-as-usual" growth and changes in the energy situation must be defined
and quantified. This step involves collecting macroeconomic projections, demographic projections, and other
estimates or assumptions regarding likely future changes. These data are then entered into the analysis system.
The initial results of these baseline scenarios should be reviewed for consistency and reasonableness, and to check
for any data entry errors.
4) Prepare Alternative Energy Scenarios: . These scenarios reflect alternative evolutions of demographic,
macroeconomic, technical, and/or policy factors. Development of alternative scenarios includes the investigation of
resource and technology options for improving end-use services at the lowest societal cost, including environmental
impacts. This involves gathering data and judging the merits of various supply and demand options (new facilities,
import/export options, efficiency improvements, fuel-switching). Cost curves can be used to as a screening
measure for developing scenarios.
5) Collect Environmental Data and Estimate Loadings related to processes and environmental issues of
concern within the baseline and alternative scenarios. In addition to gathering appropriate emission factors, this
step involves establishing the relevant cause-effect linkages (for example, does biomass energy use ⇒ land
clearing ⇒ deforestation?), and characterizing the impacts that may be more difficult to measure or quantify (for
example, ecosystem harm or aesthetic impacts). Information on loadings and direct environmental impacts may,
depending on the goals of the analysis, be used to model the transport fate, and responses of organisms and the
physical environment to pollutant discharges
6) Analyze policy options and implications, to determine how the least-cost, maximum-benefit scenario can
be achieved, and what additional costs might be involved (such as program/administrative costs, economic losses
or gains due to taxation or subsidies, etc.). Environmental externalities should be included in a comprehensive and
systematic fashion in whatever decision-guiding framework (for example, social cost-benefit analysis) is used. Other
externalities -- most notably broader socio-economic impacts --should also be included.
Note that while different approaches to pollutant transport and dose-response modeling are discussed briefly in
Section 6, they are generally beyond the scope of this guide.
Table 1.2 below provides a hypothetical table of LEAP/EDB results over a 15-year time horizon.
Emissions and impacts are typically driven (caused to change in magnitude over time) by increasing
economic activity, which leads to demands for energy services and the consequent consumption and
6
A Guide to Environmental Analysis For Energy Planners
production of various fuels. Emissions and impacts can also be modified by changing energy consumption
patterns, fuel choices, energy loss levels, technology choices, and the development of new technologies
including pollution control and other mitigation measures. As discussed in Section 5, you can use a energyenvironment modeling framework such as LEAP/EDB to create scenarios that explore the consequences of
policy interventions or alternative development patterns. Among other objectives, scenarios can seek to
minimize or reduce projected loadings as a means to achieve more environmentally sustainable energy
development.
Table 1.2:
Hypothetical LEAP/EDB Environmental Results Table
Base Case Scenario
AIR EMISSIONS
Carbon Dioxide
Sulfur Oxides
WATER EMISSIONS
Cadmium
SOLID WASTE
Scrubber Waste
LAND USE
Inundated Land Area
HEALTH AND SAFETY
Lost Work Days
1990
1995
2000
2005
Units
100
5
150
10
200
15
250
15
1000 Tonnes
Tonnes
20
30
40
40
Kg
10
20
30
30
Tonnes
10
10
10
200
Hectares
200
300
400
400
Person-Days
While falling short of providing actual accountings of environmental damage or costs, the
emissions and on-site impact results from LEAP/EDB can provide important indicators of the direction of
environmental progress or deterioration with respect to key issues such as acid precipitation, greenhouse
gas emissions, toxic emissions, and air pollution. LEAP/EDB itself contains no models to determine the
fate of pollutant emissions and their eventual health, ecological, aesthetic, and other damages.
As discussed in Section 6, physical damage estimation can be extremely difficult, and can require
rather detailed models of pollutant fate and transport, receptor (plants, animals, humans) exposure, and
dose and stress-response. In many cases, such as global climate change, acid damage of sensitive
ecosystems, or health impacts of traditional biomass cooking, scientific uncertainty as to the expected
extent of physical damages remains significant. Nonetheless, there is sufficient evidence in many cases to
estimate the magnitude of likely damages, and to suggest that specific actions can reduce the risk of these
impacts. Section 6 reviews some of the available models for impact and damage assessment. Due in part
to their complexity, environmental damage models have generally not been extensively applied by energy
planners, despite the growing importance of environmental considerations in sifting among energy choices..
Finally, we turn to the most difficult and perhaps the most important question: how does one
incorporate environmental concerns into energy sector decisions? From a decision-making perspective, the
integration of different environmental damages into a single numeraire or variable would be ideal, in order
to compare strategies and technologies with very different types of impacts (for example. hydroelectric and
coal-fired power plants). Can, or should, loadings or damages be converted to monetary estimates,
enabling their use in cost-benefit analyses? The monetization of environmental impacts — more precisely,
environmental externalities, the economic term for costs not typically counted in market prices and
decisions — is proceeding at a rapid pace. In the U.S., for instance, 29 states have acted to incorporate
Introduction
7
environmental externality costs in electric sector planning4. Internalizing environmental costs has been
termed "the wave of the future", with 85 pollution taxes already in place by 1989 among OECD countries5.
So-called market-based initiatives, are rapidly spreading worldwide. Although such initiatives remain
relatively rare among developing countries at present, there are exceptions, such as forestry levies aimed at
reducing the environmental impacts of woodfuel harvesting (though these may be of questionable efficacy
because of enforcement difficulties).
There are many alternatives among monetization methods and many alternatives to monetization.
Monetized values for emissions such as carbon dioxide or sulfur dioxide can be imputed from the costs of
emission control devices used to achieve a specified target level of emissions of a particular pollutant, or
based on the costs of the damage they lead to. Each method has distinct advantages and disadvantages.
For practical or ethical reasons, monetization may be rejected in favor of ad hoc approaches to
incorporating environmental concerns (e.g. subsides for certain environmentally-preferred options, such as
solar energy), or other techniques such as multi-objective analysis. These approaches are reviewed in a
SEI-B companion paper entitled Incorporating Environmental Externalities in Energy Decisions: A Guide
for Energy Planners. (Hill et al, 1994).
1.2 Challenges and Concerns in Quantitative Analysis
Three major challenges that face the planner who carries out a quantitative environmental analysis
include: 1) the consideration of loadings and impacts that are difficult to quantify or generalize (for
example, ecological damage, soil degradation, and aesthetic impacts), 2) large uncertainties in relationships
between loadings and damages; and 3) the comparison across seemingly incommensurate impacts (such as
balancing human health, ecological, and economic costs and benefits). In particular, for energy sources
with extensive land-use impacts such as woodfuel plantations and hydroelectric or geothermal facilities, the
overwhelming influence of site-specific factors (local climate and ecology, land use patterns) render
generalized models very difficult. The danger of biasing energy choices towards those options whose
environmental impacts are most difficult to assess or quantify -- "confusing the countable with the things
that count" -- must be avoided.
A few caveats will be echoed throughout this guide:
•
there is no single or straightforward recipe for including environmental concerns in energy
analysis;
•
ease of quantification can be seductive, and an initial prioritization of concerns is thus
important in order to avoid unnecessary focus on easily countable impacts that may be orders
of magnitude less important than more intractable environmental and/or social issues;
•
environmental impacts are complex, often non-linear (that is, not varying directly with the
amount of energy consumed or even the amount of a pollutant released), with pathways that
can depend on factors beyond the general scope of the energy sector (such as
4 Of these, 19 states have issued orders or passed legislation requiring utilities to include these costs in planning or new
capacity bidding processes. R. Ottinger, "Consideration of Environmental Externality Costs in Electric Utility Resource
Selections and Regulation", in Energy Efficiency and the Environment: Forging the Link, Vine, E. et al., eds. American
Council for an Energy-Efficient Economy, Washington, DC, 1991.
5 Ibid , p. 190.
8
A Guide to Environmental Analysis For Energy Planners
biomass/deforestation linkages, the connection between settlement and transportation patterns
and urban air pollution, etc.);
•
there are no easy, objective methods for comparisons across classes of impacts (human health,
agricultural production, aesthetic value, etc.). Since some method of numerical valuation of
environmental impacts (such as ranking or the application of externality costs) is inevitably
required, difficult and often rather subjective judgments must be applied.
With these caveats in mind, one can nonetheless usefully apply tools of integrated, quantitative
energy-environment analysis. The use of tools such as LEAP/EDB may only lead to partial answers in
terms of environmental outcomes and costs, but these can be important inputs for use in directing energy
policy toward more sustainable paths. Other complementary and non-quantitative approaches must also be
considered, including the comparative environmental assessments noted above. The alternative to the
integrated analysis of the environmental impacts of energy choices is quite often a “business-as-usual”
mode where the consideration of environmental issues in energy policy decisions is limited to immediate
crises (such as deforestation and a perceived linkage to energy) or funders' concerns (as has to a large
degree precipitated the recent spate of global warming analyses). This "reactive" mode generally fails to
avoid foreseeable problems or address long-term local concerns. Attention then focuses on more costly
mitigation actions (clean up, reforestation, sea wall construction, etc.). Planting trees and/or restricting
access to an area in order to help regenerate a natural forest is, for example, almost inevitably more
expensive and difficult to achieve than are the alternatives to land clearing. An ounce of prevention, as the
saying goes, is worth a pound of cure. As described in the next section, we are now faced with numerous
global, regional, and local environmental concerns that require a rethinking of energy policy, and the
application of appropriate analytical approaches and tools, to avoid the “pound of cure”.
Introduction
9
Table 1.3:
Glossary of Terms as Defined in this Guide
Biodiversity: The extent to which an ecosystem has a few or many different species and types of
organisms is termed its biodiversity. While some ecosystems naturally have relatively few different
types of organisms (arctic ecosystems are examples here), ecosystems with a greater diversity are often
(though not universally) thought to be more “healthy” and robust. Loss of biodiversity can occur as a
result of pollutant stresses, land use change, over-harvesting of plants or animals, or changes in climate.
Deforestation, Desertification, Devegetation, or just plain Degradation: These terms refer to the
process by which lands which formerly were covered by forests or woodlands are changed, by timber or
fuelwood harvesting, fire, clearing for agriculture, or other land-use changes, to lands that have reduced
biomass productivity and reduced vegetation cover. In the extreme case of desertification, the loss of
vegetation on lands in dryer climates can allow desert land types to encroach and take over.
Dose/Response: The relationship between the amount of a pollutant (or other chemical) absorbed or
applied to a plant or animal (or area of an ecosystem) and the effect of that pollutant. Doses are often
measured in terms of unit mass of pollutant per unit mass of plant or body weight (milligrams per kg, for
instance) or per unit area or volume. Responses may be a fraction of the population likely to die or
become ill, or other changes.
Ecosystem: This is a generic term for a system that includes a community of organisms, including
animals, plants, and microorganisms, and their interactions with the environment (Freedman, 1989).
Effect: Effects, as used in this Guide and in EDB, are the direct results, including environmental
loadings (see below) and direct health and safety impacts, of the operation of energy technologies.
Examples of effects include carbon dioxide emissions to the atmosphere, emissions of mercury to water,
solid wastes applied to the land, and accidental injuries during fuel extraction.
Emission Factor or Coefficient: A quantitative measure of the emission of a pollutant per unit of
energy use, transformed, or produced by a given energy technology. Examples here are kilograms of
carbon dioxide per tonne of coal burned, or grams of slag produced per tonne of oil shale processed.
Energy Processes refer to the combination of technological, behavioral, and operational conditions. A
process can be as precise as a specific as oil refinery, where on-site measurements have been made
and its operation is simulated in LEAP. Or it can be as general as an average for all industrial boilers.
The detail of process specification will depend on the nature of the scenario building exercise and
available data on loadings.
Impact: An environmental impact of an energy-sector device or process is what happens to plants,
animals, humans, or ecosystems as a result of the use of that device or process. Direct impacts are
those that occur as a direct result of the use of the device or process, such as mining deaths occurring
during coal extraction. Indirect impacts require the transport of a pollutant or some other link between
the energy device or process and the ultimate environmental effect. The impact of sulfur dioxide
emissions from fuel combustion on lung disease would be called an indirect impact because the sulfur
dioxide must be transported (in the air) between the site where the fuel is used and the person affected
by the emissions.
Loadings: Loadings include air and water emissions, land use and materials requirements, land
degradation and habitat loss, and on-site health and safety impacts. Loadings, as we use the term here,
do not include indirect impacts -- such as the emissions from the waste disposal vehicles in the coal
power plant example cited earlier in Section 1 -- or impacts and stresses that occur beyond the
immediate site of energy use. For example, a coal plant's loadings would include nitrogen oxide and
sulfur oxide emissions from the stack, but not the tropospheric ozone and acid precipitation that might
result from the emissions due to atmospheric chemistry and pollutant transport.
10
A Guide to Environmental Analysis For Energy Planners
Table 1.3 (continued):
Loading Factors: These are typically expressed in loadings (see above, and also see the definition for
emission factors) divided by the unit of energy flow of an energy process. Loading factors include
emission factors for air and water emissions or indicators of on-site health and safety risks (for example,
1 injury per 100,000 tonnes coal mined). The appropriate measure for energy flow, the denominator of
the loading factor, depends upon the process considered. (See Section 4) For instance, the emissions of
sulfur oxides (SOx) from a coal-fired electric facility can be expressed in terms of grams per kilowatt-hour
produced or tonnes of coal consumed. In either case, the relationship between energy flow and loadings
for a given process is linear. That is, if electricity production from a facility doubles, without any other
changes, the use of a single factor implies that loadings will double as well. While for many loadings,
carbon dioxide emissions from fossil fuel combustion being a prime example, this simple relationship
holds, for others, such as land use by hydro or other energy facilities, the relationship is less clear.
Medium/Media: These are the parts of the ecosystem to which pollutants are discharged, including the
atmosphere (air), rivers, stream, lakes, and oceans (water), and land (soil). The media to which a
pollutant is discharged determines in large part the way in which it is transported to the organisms and
ecosystems it affects.
Pathway: The way in which energy use, production, or transformation exerts an influence on (affects) a
receptor (see below) is the pathway by which the impact occurs.
Receptor: A receptor is a plant, animal or ecosystem affected by an energy system, either directly (such
as coal mining accidents) or indirectly through pollutant emissions or other effects.
Stress: Stress defined by Freedman (1989) as the physical, chemical, or biological constraints that limit
the potential productivity of the biota [the plants and animals in an ecosystem]. Any environmental
influence that causes measurable ecological detriment.” An air pollutant that reduces the growth of a
plant would be exert a stress on that plant.
Major Environmental Problems Associated with Energy Activities
11
2. Major Environmental Problems Associated with Energy Activities
2.1 Introduction
The connection between energy use and environmental degradation is not surprising. From the
polluted air of many urban areas to denuded hillsides that no longer provide easy access to woodfuels, the
signs of this connection are increasingly visible. Acid rain, oil spills, global warming, toxic wastes, habitat
loss, population displacement: the number of environmental issues associated with energy activities is both
alarming and challenging to those seeking to address them in a comprehensive manner. Adding to this
challenge are the many dimensions of each problem, from their underlying causes (for example, poverty or
infrastructure policies) to their final impacts. As depicted in Figure 2.1, numerous factors can influence the
nature and extent of environmental damages, and consideration of these factors can suggest different
options for reducing environmental impacts.
Figure 2.1:
Selected Pathways from Energy Activity to Environmental Damage
UNDERLYING
CAUSES
Infrastructure
Economic
Agricultural Policies
Financial Constraints
Poverty
Land Tenure
Consumption Patterns
ENERGY
ACTIVITY
Facility Construction
Fuel Extraction
Refining& Conversion
Fuel Combustion
ENVIRONMENTAL
EMISSION/INSULT
Air & Water Emissions
Solid Waste
Land Clearing
Population Displacement
TRANSPORT
Air
Water
Soil
RESPONSE/
DAMAGE
Ecosystem
Human Health
Aesthetics
Land Degradation
Biodiversity
Economic Harm
Although this document is focused upon the linkages between energy activities and environmental
loadings and damages, the importance of other dimensions cannot be overlooked6. Underlying dynamics
and causal factors related to development and socio-economic relations can either foster or undermine
otherwise well-intended policies (witness, as an example, the difficulties encountered by many reforestation
and wood-energy plantation efforts). Transport of emissions can lead to trans-boundary problems, such as
acid deposition and global warming, that cannot be resolved solely on a national level. There are also
broader issues of who benefits and who loses with environmentally damaging activities. It has been said
that woodfuel issues cast an urban shadow over the rural areas that bear the brunt of the impacts of wood
harvesting, as few rural residents benefit from this resource extraction. A similar argument can be made
about global warming under the current North-South patterns of fossil fuel use and related carbon dioxide
emissions, as depicted in Figure 2.2.
6 For a discussion of the models and approaches for looking at some of the other aspects of the system, for example, transport-
impact models, etc., see World Bank. Environmental Assessment Sourcebook, Volumes I-3, Environment Department, World
Bank Technical Paper 139, Washington DC, 1991. The approach described here is not intended to substitute for, rather to
stimulate, more thorough project-specific environmental analysis, such as that typically undertaken in an Environment Impact
Assessment.
12
A Guide to Environmental Analysis For Energy Planners
Figure 2.2:
The Regional Pattern of CO2 Emissions from Fossil Fuel Combustion
N. Amer.
E. Eur/SU
Oceania
W. Eur.
Mid. East
L. Amer.
CP Asia
Africa
S&E Asia
0
5,000
10,000
15,000
20,000
kg CO2 per Capita
This chapter groups the major energy-environmental issues by relative geographic scale of
impact: global, regional, and local. Impacts with a global scale may originate from local activities,
which, due to the longevity and transport of emissions, or to the nature of the impact, affect global
environmental conditions. These issues include global climate change from greenhouse gas emissions,
stratospheric ozone depletion, and habitat destruction with the associated reduction of global biodiversity.
In contrast, some energy activities result in emissions (e.g. acid precursors, SOx and NOx, or the
mobilization of long-lived toxic contaminants) that lead to damage tens or hundreds of kilometers away.
We refer to these as regional issues. Finally, local issues refer to situations where impacts generally occur
at or near the site of energy use or production, such as indoor and urban air pollution, groundwater
contamination, and solid waste production.
The groupings that we use, shown in Table 2.1, are far from definite or universal. The
classifications are intended to suggest the scope of analysis and action necessary to address each issue. For
example, global and regional concerns are more likely to involve transboundary issues requiring
cooperation between countries, such as international or regional agreements necessary to mitigate sources
of pollution, and may be more difficult to fully address on a solely national or subnational basis.
Major Environmental Problems Associated with Energy Activities
13
Table 2.1:
Major Energy-Environment Issues by Scale
GLOBAL ISSUES
o
Global Climate Change
o
Stratospheric Ozone Depletion
o
Reduction of Biodiversity
REGIONAL ISSUES
o
Water and Land Use and Degradation
o
Ocean Contamination (Oil spills, etc.)
o
Mobilization of Toxic Contaminants
o
Acid deposition
o
Radioactivity and Radioactive Wastes
LOCAL ISSUES
o
Urban Air Pollution
o
Indoor Air Pollution
o
Localized Surface and Groundwater Pollution
o
Solid and Hazardous Wastes
o
Electromagnetic Fields
o
Occupational Health and Safety
o
Large Scale Accidents
o
Aesthetic and Other Concerns (e.g. Audible Noise, Visual Impairment)
2.2 Global Issues
While some environmental issues are either so widespread (such as oil spills) or have impacts that
can be sufficiently far removed from their source (radioactive emissions) as to arguably be considered
world-wide in scope, three issues most clearly have implications for the well-being of the entire planet.
These are global climate change, sometimes (but not entirely correctly) referred to as "the greenhouse
effect", the depletion of stratospheric ozone, and reductions in biodiversity. The first two issues are
occasionally confused, since some of the same chemical compounds have roles in both processes, but they
pose quite distinct threats.
2.2.1 Global Climate Change
"Global warming", “climate change”, and the "greenhouse effect" are common expressions used to
describe the threat to human and natural systems resulting from continued emissions of heat-trapping or
“greenhouse” gases (GHGs) from human activities. These emissions are changing the composition of the
atmosphere at an unprecedented rate. While the complexity of the global climate system makes it difficult
to accurately predict the impacts of these changes, the evidence from modeling studies, as interpreted by the
world’s leading scientists assembled by the Intergovernmental Panel on Climate Change (IPCC), indicates
that global mean temperature will increase by 1.5 to 4.5º C with a doubling of carbon dioxide
concentrations, relative to pre-industrial levels7. Given current trends in emissions of greenhouse gasses,
this doubling--with its attendant increase in global temperatures, would likely happen in the middle of the
7 Intergovernmental Panel on Climate Change. 1992. Climate Change 1992: The Supplementary Report to the IPCC Scientific
Assessment. J. T. Houghton, B. A. Callander and S. K. Varney, eds. Cambridge, U.K.: Cambridge University Press, p.5.
14
A Guide to Environmental Analysis For Energy Planners
21st century. For reference, a global increase of 2º C from today’s levels would yield global average
temperatures exceeding any the earth has experienced in the last 10,000 years, and an increase of 5º C
would exceed anything experienced in the last 3,000,000 years. Moreover, it is not simply the magnitude
of the potential climate change, but the rate of this change that poses serious risks for human and
ecosystem adaptation, with potentially large environmental and socioeconomic consequences.
The greenhouse effect itself is a relatively well-understood natural phenomenon, first mentioned as
early as 1827 in a paper by the physicist-mathematician Jean-Baptiste Fourier. The earth receives a
relatively constant amount of energy from the sun in the form of incoming solar radiation. The atmosphere
and surface of the earth reflects some of this radiation, most of which is in the form of visible light, directly
back into space, but absorbs the majority. An amount of energy equal to that in the radiation absorbed is
ultimately re-emitted to space as thermal (heat) or "outgoing" radiation, thereby maintaining an energy
balance between incoming and outgoing energy. This balance keeps the earth’s temperature at an
equilibrium level. Figure 2.38 below shows the basic mechanisms of this "greenhouse effect".
Figure 2.3: The Greenhouse Effect
SUN
Some solar radiation is reflected
by the earth and the atmosphere
ATMOSPHERE
Solar radiation
passes through
the clear
atmosphere
Most solar radiation is
absorbed by the earth’s
surface and warms it
EARTH
Some of the infra-red radiation is
absorbed and re-emitted by the
greenhouse gases. The effect
of this is to warm the surface and
the lower atmosphere.
Infra-red
radiation is
emitted from the
earth’s surface.
The essence of the greenhouse effect is that particular trace or “greenhouse” gases in the
atmosphere absorb some of the outgoing radiation on its way to space from the surface of the earth. These
gases, principally water vapor (H20), carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and
ozone (O3), together act as a transparent atmospheric "blanket" that allows sunlight to warm the earth but
keeps infra-red radiation (heat) from leaving the earth and radiating out to space
Without this atmospheric “blanket” of trace gases, the equilibrium surface temperature of the earth would
be approximately 33° C cooler than today’s levels, averaging -18ºC rather than +15ºC, and making the
earth too cold to be habitable. It is this blanketing effect of the atmosphere that is referred to as the
greenhouse effect. A greenhouse is a useful analogy; the atmosphere behaves somewhat like the glass pane
of a greenhouse, letting in visible or short-wave radiation, but impeding somewhat the exit of thermal
energy, thereby increasing the equilibrium temperature inside the greenhouse.
The present concern with global warming does not center on the natural greenhouse effect of the
atmosphere on global equilibrium temperature and climate. Rather, it arises from the potential additional
8 After IPCC, 1990.
Major Environmental Problems Associated with Energy Activities
15
global warming that may occur due to the rapidly increasing concentrations of heat-trapping greenhouse
gases. Measurements taken at remote locations around the globe have revealed that current concentrations
of greenhouse gases in the atmosphere substantially exceed their pre-industrial levels. The primary human
activities that are responsible for this growth in atmospheric concentrations of these gases are the
combustion of fossil fuels and the reduction of carbon stored in biomass through conversion of forests and
other natural land types to settlements, agricultural land, and other uses.
The combustion of all carbon-based fuels, including coal, oil, natural gas, and biomass, release
carbon dioxide (CO2) and other "greenhouse gases" to the atmosphere. Over the past century, emissions of
greenhouse gases from a combination of fossil fuel use, deforestation, and other sources have increased the
effective "thickness" of the atmospheric blanket by increasing the concentration of greenhouse gases (or
GHGs) in the troposphere, or lower part of the atmosphere (ground level to about 10-12 km). It is this
"thicker blanket" that is thought to be triggering changes in the global climate. Table 2.2 lists the most
important greenhouse gases, together with their major sources, current concentrations, and the rate at which
they have recently been increasing in the atmosphere.
16
A Guide to Environmental Analysis For Energy Planners
Table 2.2:
Overview of Common Greenhouse Gases9
Gas
Principal Sources
Current Rate of
Emissions and
Increasing
Concentration
Global Warming
Potential (100year time
horizon)
Approximate
Contribution
to Warming
Carbon Dioxide
(CO2)
- Fossil Fuel Combustion
- Deforestation
- Cement Manufacture
- 26,000 Tg/yr emitted
- 0.5%/yr increase in
concentration
1
84%
Methane (CH4)
- Natural Gas and Oil Production
- Natural Gas Pipelines
- Coal Mining
- Fossil Fuel Combustion
(minor)
- Agriculture (Rice Cultivation,
Enteric Fermentation)
- Waste Disposal
- 300 Tg/yr emitted
- 0.9%/yr increase in
concentration
24.5
11%
Nitrous Oxide (N2O)
- Fossil Fuel Combustion
(minor) - Biomass Burning
- Agriculture (Fertilizer Use)
- 6 Tg/yr emitted
- 0.8%/yr increase in
concentration
320
5%
Chlorofluorocarbons
(CFCs) and related
Gases (HFCs and
HCFCs)
- Industrial Uses Including
Refrigerants, Foam Blowing,
Solvents, Fire Retardants
- 1 Tg/yr emitted
- 4%/yr increase in
concentration
140-12,100,
depending on gas
--
Gases That May Have Indirect Effects on Climate Change
Carbon Monoxide
(CO)
- Fossil Fuel Combustion
(especially vehicles)
- Biomass Burning including
Biomass Fuel Combustion
- 200 Tg/yr emitted
--
--
Nitrogen Oxides
(NOx)
- Fossil Fuel Combustion
- Biomass Burning
- 66 Tg/yr emitted
--
--
Non-Methane
Hydrocarbons
- Fossil Fuel Combustion
- Solvent Use
- 20 Tg/yr emitted
--
--
A number of gases may also indirectly affect global climate. Carbon monoxide (CO), nitrogen
oxides (NOx), non-methane hydrocarbons (NMHC), and methane are all thought to contribute indirectly to
global warming by affecting the atmospheric concentration of other greenhouse gases (such as tropospheric
and stratospheric ozone)10. Because of incomplete understanding of the chemical processes involved, these
indirect contributions to warming are more uncertain than the contributions of the direct greenhouse gases
(CO2, CH4, N2O, CFCs). This is reflected in the recommendation that indirect global warming potentials
(GWPs), indicators of the relative warming effects of each gas, are no longer suggested by the IPCC for
CO, NOx, NMHC, and CH4. In its 1992 Supplement to its original 1990 Report, the IPCC stated that
earlier reported indirect GWP values “are likely to be in substantial error, and none of them can be
9 Based on Leggett, 1990, IPCC, 1990, IPCC 1992, and IPCC 1994.
10 Methane has both direct and indirect effects.
Major Environmental Problems Associated with Energy Activities
17
recommended.”11. The GWP values shown in Table 2.2 are from the latest IPCC Assessment (IPCC
1994, page 28).
Some gases may have cooling effects as well. Recent evidence suggests that the overall role of
chlorofluorocarbons (CFCs), once thought to be major contributors to global warming, is no longer clear.
By reducing the concentration of stratospheric ozone, CFCs may have a cooling effect approximately
canceling out the direct warming effect of the CFC molecules themselves. The emission of sulfur
compounds (such as SO2), which leads to the formation of sulfate aerosols, may have a cooling effect in the
Northern Hemisphere. However, this cooling effect, like the sulfate aerosols themselves, is highly localized
and relatively short-lived.
The role of water in the atmosphere is complex. Global warming will increase evaporation, and
thus increase moisture in the atmosphere. Since water vapor acts as a greenhouse gas, this leads a
warming feedback effect12. Increased water vapor will also likely increase cloud formation. However, the
net feedback effect of cloud formation is uncertain, depending on the type of clouds that are formed, since
water vapor in clouds can both reflect incoming sunlight and trap outgoing radiation.
While the extraction, transportation, and use of energy is not the only source of greenhouse gases,
the sector contributes, all told, more than half of the overall commitment to global warming. Though
carbon dioxide from fossil fuel combustion is the best known and most important greenhouse gas,
combustion also releases other GHGs, and fossil fuel extraction, transmission and distribution are
important sources of methane and other hydrocarbons, as shown in Table 2.2.
Under ideal conditions, the use of biomass fuels will not lead to net CO2 emissions. Plants take up
carbon dioxide as they grow to construct the organic (carbon-containing) biological molecules that make up
the bulk of their (dry) mass. When the biomass in the plants is eaten, burned, or decomposes, the carbon
is released again (in large measure) as CO2, and is returned to the pool of carbon dioxide in the atmosphere.
This recycling is part of a natural process called the carbon cycle. If the rate at which biomass is
harvested for fuel is balanced by the rate of biomass growth, then no net CO2 emissions will occur. In
cases where biomass is removed but does not (or is not allowed to) grow back, the use of biomass fuels use
can yield net CO2 emissions. This is the case in instances where fuelwood consumption in a region takes
place at a rate faster than forests can grow back, or when carbon in the soil is depleted by sub-optimal
forestry or agricultural practices.
While there is now general (but not total) agreement among atmospheric scientists that increases in
atmospheric concentrations of GHGs will result in an average increase in global temperatures -- assuming
current rates of emissions continue -- some uncertainty remains. There are complicated interactions and
"feedbacks" between the atmosphere, the oceans, the continents, and the biosphere. While very powerful
and complex climate models now exist for analyzing the interactions between GHG emissions and climate,
there still remain major scientific uncertainties and modeling challenges yet to be solved. For example,
when measurements of the rate at which CO2 concentrations are increasing in the atmosphere are compared
with the rates at which CO2 is estimated to be emitted by fossil fuel combustion, it appears that a
11 IPCC 1992, p. 14-15.
12 A feedback happens when a change in some quantity B brought about by a change in A has a further effect, or feedback, on
A itself. When your body becomes too hot, for example, water evaporates from your skin at a greater rate, and you cool down.
This is called a negative feedback, as the change in the second variable (evaporation) reduces the first (skin temperature). An
example of a positive feedback loop with several links that involves the energy sector might be the following: Increased use of
air conditioning leads to increased emissions of GHGs, which increases levels of GHGs in the atmosphere, which leads to
higher global temperatures, which leads to further increased use of air conditioning.
18
A Guide to Environmental Analysis For Energy Planners
substantial amount of the fossil carbon dioxide is "missing", that is, is not present in the atmosphere. While
various "sinks", or places in the earth/ocean/atmosphere system where this CO2 may have ended up, have
been postulated -- most notably, the deep, relatively unmixed portions of the oceans -- the uncertainty in
this key parameter underscores lack of complete understanding of the full suite of climate system
interactions.
In addition, our climate has quite a lot of natural variability on many scales -- year-to-year,
century-to-century, millennium-to-millennium, and longer. This natural variability, as shown by the cycles
of cooler and warmer periods13 has made definitive detection of warming induced by human activity
difficult. Compounding this problem in detection are the effects of other events beyond human control.
Large volcanic eruptions, for example, can inject large amounts of dust into the stratosphere, the part of
the atmosphere lying above the troposphere, which can cause global temperature to be slightly cooler than
they would have been, sometimes for several years. For example, the recent eruption of Mount Pinatubo in
the Philippines threw sufficient debris into the stratosphere to explain, according to several climate
modellers, the cooler temperatures experienced globally in 1992. This drop broke a trend of steadily
increasing global average temperatures. Seven of the eleven warmest years in recorded history occurred in
the 1980s, and 1991 was the warmest year ever.
Warming of the earth may, in turn, have numerous secondary effects, some of which have
potentially serious impacts of the well-being of both humans and the plants and animals with which we
share this planet. These effects include an increase in sea levels due to melting of polar ice, changes in
precipitation patterns, and changes in vegetation. The timing and spatial distribution of these effects
around the globe are as yet extremely uncertain. The implications of these effects on human populations
are discussed briefly below.
•
•
Sea level rise. Two processes could contribute to this phenomenon: thermal expansion of the
oceans, and melting of polar ice caps, snow cover and glaciers. Many coastal communities,
particularly those in large alluvial flood plains and low-lying islands, are particularly vulnerable.
Low-lying cities and croplands may be partially submerged and/or subject to more frequent
flooding by tides and storms, and highly productive coastal ecosystems that humans depend on -particularly estuaries -- may suffer a loss in productivity. This loss in productivity is due both to
increasing salinity of surface and ground waters and to increasing water levels. Furthermore, as
highly reflective polar and glacial ice and snow melt to expose less-reflective earth or open sea
water, the earth becomes a better absorber of solar radiation. This may further increase the rate at
which global temperatures rise. Similarly, as the arctic tundra warms, methane could be released
from methane hydrates14 and contribute to further warming.
Increased climatic variability and storm intensity: Changes in temperature are likely to create
changes in wind and precipitation patterns; that is, some places will become wetter, others drier. In
addition, the timing of wet and dry seasons may change, and what precipitation does fall may do so
in a more concentrated fashion (i.e. as storms) or more gradually. At present the various climate
models are not in full agreement as to which regions will be affected in what way, but given the
importance of rainfall patterns on the ability of agriculture to sustain human populations,
particularly in heavily populated areas (southeast Asia, for example), any changes in precipitation
are of concern. Another prediction of some climate models is that severe storms, including
tropical typhoons and hurricanes, will become more frequent and/or more severe, posing an added
13 See, for example, Leggett, 1990, pages 20 and 21.
14 Methane hydrates are molecules of methane “locked up” with water molecules in ice structures. When these structures
melt, the methane molecules are released to the atmosphere as methane gas.
Major Environmental Problems Associated with Energy Activities
•
19
threat to coastal and island populations. Finally, changes in precipitation will affect the
availability and quality of fresh ground and surface waters.
Changes in vegetation: Changes in the distribution of plants brought on by changes in temperature
and precipitation also have implications for human well-being. Some interpretations of climate
model results show the "grain belts" of the Northern hemisphere shifting north by hundreds of
kilometers. However, it is uncertain whether the full set of conditions to maintain agricultural
productivity will remain. Forests, animal habitats, and ecosystems as whole may be unable to
tolerate climatic changes, may be unable to migrate as quickly as climates shift to other areas. At
the same time, higher levels of CO2 in the atmosphere increase the rate at which certain plants
grow (all else being equal and assuming no other growth limiting factors), and higher temperatures
would benefit some plant species, while being detrimental to others.
For a detailed discussion of these and other climate change concerns, see the compendium of essays
in SEI's recent volume on Confronting Climate Change, 1992, Mintzer, I. ed.
2.2.2 Stratospheric Ozone Depletion
Depending upon where it occurs, ozone (O3) plays two very different roles in the atmosphere. In
the troposphere, where it is the produced through the interaction of sunlight, NOx, and VOCs15, ozone can
be a major local and regional air pollutant that can cause acute respiratory symptoms and damage to
materials, crops, and forests. Tropospheric ozone is also a greenhouse gas (see above).
In the stratosphere, however, ozone is naturally occurs in much higher concentration and it plays a
different, beneficial role. The stratospheric ozone layer intercepts much of the ultraviolet (UV) part of the
radiation emitted by the sun. Invisible to the human eye, this UV radiation increases the risk of skin
cancers, cataracts, and immune system problems in humans.
In recent years, dramatic reductions in stratospheric ozone concentrations, up to 50% in some polar
regions, have been recorded. Smaller reductions of 5-10% have been detected in middle and upper
latitudes, while tropical regions appear to be unaffected thus far. Sustained reductions of 10% in ozone
concentrations could lead to a 25% increase in non-melanoma skin cancers and a 7% increase in eye
damage from cataracts. (World Bank, 1992).
Furthermore, exposure to UV radiation can damage agricultural yields, phytoplankton (an essential
food chain element of marine environments), and terrestrial ecosystems in two general ways. First,
ultraviolet light causes damage to biological functions in plants and microorganisms, which can result in
stunted growth and lowered viability. Second, UV radiation can modify the genetic material in plant and
animal cells (DNA), resulting in potential damage to cell function and mutations that can influence the
viability of seeds, pollen, eggs and sperm16. Since some species are more resistant to UV radiation than
others, increases in such radiation could alter the species balance in some ecosystems. Increased levels of
UV radiation also accelerate the degradation of some materials, such as paints and plastics.
15 Volatile Organic Compounds, a broad class of emissions that includes many of the same species of hydrocarbon molecules
as Non-Methane Hydrocarbons (previously mentioned), as well as methane itself.
16 Recently, articles in the journal Science have suggested a link between increase UV radiation and the reduction in the
number of amphibians in many locations. Amphibian eggs, which often include a transparent “jelly”-like layer around the
developing embryo, are thought to be particularly sensitive to UV radiation.
20
A Guide to Environmental Analysis For Energy Planners
Several human activities can lead to the stratospheric ozone destruction. In the early 1970's,
concern over the ozone-depleting potential of water vapor and nitric oxide in the exhaust of a proposed fleet
of super-sonic transport (SST) planes played a major role in limiting the deployment of SSTs17.
Chlorofluorocarbons (CFCs), however, pose the largest and most immediate threat to the ozone layer.
Certain energy-sector equipment -- most notably electric refrigerators and air conditioners -- contain CFCs,
which are also used for purposes such as cleaning of computer chips and in plastic foam manufacture.
Released through leakage or when old appliances are discarded, CFCs rise to the stratosphere, where
reaction with sunlight can yield free chlorine, a catalyst for ozone destruction. (see Box 2.1, below).
Mounting international concern led to signing of the Montreal Protocol on Substances that Deplete
the Ozone Layer in 1987, with subsequent amendments that commit the signatory governments to a phaseout of CFCs and similar substances in industrialized and developing countries by the years 2000 and 2010,
respectively. The phase-out of some CFCs have already begun, and some industries are finding that the
costs of finding and using alternatives to ozone depleting substances is less than expected18.
The principal intersection between the energy sector and ozone depletion lies in demand-side
management programs that affect the stock and fate of CFC-containing appliances, or in appliance
efficiency standards that influence the design or import of new equipment. (A highly touted U.S. EPA
program entitled "Golden Carrot", has offered financial incentives to manufacturers of high-efficiency lowCFC refrigerators.) In addition, demand-side management (DSM) programs that encourage the
replacement of existing inefficient equipment with more efficient models can accelerate CFC release in the
absence of measures to reclaim the used CFCs.
17 The only SST in commercial use, the French/British "Concorde", has a smaller engine and is lower-flying than the US fleet
of SSTs that was proposed, and thus poses less of a threat.
18 For example, CFC-based solvents used for cleaning electronic parts are being replaced, in part, by inexpensive, water-based
solvents based on citrus products.
Major Environmental Problems Associated with Energy Activities
21
BOX 2.1:
THE PRODUCTION AND DESTRUCTION OF STRATOSPHERIC OZONE
Ehrlich, Ehrlich and Holdren (1977) describe the process of stratospheric ozone production and
destruction as follows:
"The stratospheric pool of ozone is the result of a balance between continuous processes that
produce and destroy this substance. (The size of the pool varies with latitude and with time in response
to a variety of natural factors.) Production takes place when molecular oxygen (O2) is split by ultraviolet
solar radiation and the resulting oxygen atoms (O) attach themselves to other oxygen (O2) molecules:
O2 ----> O + O
O + O2 ----> O3.
"Destruction takes place by means of several different reactions, in which the net results are
either:
O + O3 ----> O2 + O2
or
2 O3 ----> 3 O2.
"The destruction reactions proceed most rapidly in the presence of certain catalysts [molecules
that chemically speed up the reactions]: the hydroxyl radical HO (which comes from water vapor in the
stratosphere), nitric oxide (NO) and atomic chlorine (Cl). All of them are scarce in the natural
stratosphere, although crucial to its chemistry. Activities of civilization that change the stratospheric
concentrations of these catalysts also change the rate at which ozone is destroyed, thereby altering the
production-destruction equilibrium and possibly reducing the atmospheric pool of ozone."
2.2.3 Biodiversity and Habitat Loss
Biodiversity is perhaps the most discussed ecological issue of recent years. The variety of living
organisms may be significantly affected by human activities associated with energy supply and use,
particularly those that lead to local or global climate change or alter land use patterns. The term
"biodiversity" encompasses not only the variety of plant and animal species -- including the less visible
world of microscopic plants, insects, fungi and bacteria -- inhabiting a given area, but also the genetic
variability inherent among individual organisms within a species, variability that contributes to the ability
to adapt to changing circumstances. Scientists have identified and named about 1.7 million of the
estimated 10 to 30 million species (Freedman, 1989) that inhabit the earth19. An estimated 86 percent of
these species inhabit tropical regions.
Freedman (1989)20 summarizes three classes of reasoning -- philosophical, utilitarian, and
ecological -- that argue for the maintenance of biodiversity:
"1. One class of reasons is essentially philosophical, and it revolves around the esthetics of
extinction. The central questions are (1) whether humans have the right to act as the exterminator
of unique and irrevocable species of wild biota and (2) whether human existence is somehow
impoverished by the tragedy of anthropogenic extinction [extinctions caused by humans]. These
19 Note that 10 to 30 million species may be an under-estimate--some researchers argue for an ultimate figure on the order of
100 million.
20 Page 267.
22
A Guide to Environmental Analysis For Energy Planners
are deeply philosophical issues, and they are not scientifically resolvable. However, it is certain
that few people would applaud the extinction of a unique species of organism.
"2. A second class of reasons is more utilitarian. Humans are not isolated from the biosphere.
We take advantage of other organisms in myriad ways for sustenance, shelter, and other purposes,
including the functions that they may play in regulating or carrying out ecological processes. If
species become extinct, then their unique biochemical, ecological, and other properties are no
longer available for actual or potential exploitation by humans.
"3. The third class of reasons is essential ecological, and involves the possibly essential roles of
species in maintaining the stability and integrity of ecosystems, and their roles in nutrient cycling,
productivity, trophic dynamics, and in other important aspects of ecological structure and function.
In only a very few cases do we have sufficient knowledge to evaluate the ecological ‘importance’ of
particular species. It appears that an extraordinary number of species could disappear in the
current wave of anthropogenic extinctions before they have been studied in this respect."
The Box 2.2, below, describes an example of the utilitarian value of biodiversity, the case of an
obscure tropical plant that has become important to human well-being and commerce, the rosy periwinkle
from Madagascar.
BOX 2.2:
AN EXAMPLE OF THE DIRECT ECONOMIC VALUE OF BIODIVERSITY
(Adapted from Freedman, 1989)
The rosy periwinkle is a flowering plant found on the island of Madagascar, off the coast of
southern Africa. By chance, this plant was included in a screening of a wide sample of different wild
plants for their possible cancer-fighting properties. Its extracts were found to counteract the
reproduction of cancer cells, and the plant was subsequently found to contain compounds of the type
called "alkaloids", which the plant itself probably contains to make it unpalatable or toxic to insects and
other herbivores (plant-eaters). The use of drugs based on these compounds--it takes 530 kg of plant
material to make just 1 gram of drug worth $200--has been notably successful in treating several types of
human cancers, including Hodgkin's disease and childhood leukemia. As the rosy periwinkle's natural
habitat is currently threatened by expanding agriculture and lumber harvesting, it is fortunate that its
beneficial properties were discovered before it became extinct. Thus, even to those who might contend
that human needs and commerce must come before aesthetic or moral arguments, such as the intrinsic
value of biodiversity, the possible foregone economic and practical uses of lost species must be
recognized as important and irrevocable.
Several energy supply options can affect biodiversity, as listed in the Box 2.3, below. Facility
construction and resource extraction can disturb natural land areas and thereby endanger sensitive
ecosystems. By their nature, some energy resources -- surface-mined coal, biomass, solar, and wind -imply particularly large land requirements. However, the extent of actual harm depends on several factors,
including the previous land use, the sensitivity of local ecosystems, the reversibility of changes, and the
specific practices employed. In some cases, such as degraded land converted to a multiple-species biomass
plantation, biodiversity might actually be enhanced. Measures such as reclamation can reduce the impacts
of coal surface mining (the removed soil is pushed back over the area mined and the area is replanted), but
the original flora and fauna may not fully return. Central-station solar technologies can cover large desert
or other ecosystem areas, while roof-top solar collectors ostensibly sacrifice little in terms of natural
habitat. Hydroelectric developments inundate areas behind dams and change the timing and amount of
water and sediment flows below them, potentially affecting diversity in aquatic ecosystems and the other
Major Environmental Problems Associated with Energy Activities
23
animals that depend on them. Finally, emissions from fuel combustion or other energy-related activities
(e.g. releases of radioactivity from nuclear plants) may decrease biodiversity by directly or indirectly
adding to the stress on selected plants and animals. Acid deposition can threaten acid-sensitive plants,
while encouraging growth of other acid-loving ones.
BOX 2.3:
ENERGY SOURCES WITH POTENTIAL IMPACTS ON BIODIVERSITY
TECHNOLOGY
MECHANISM OF IMPACT
Biomass Plantations
Conversion of natural land to managed monoculture (such as Eucalyptus
plantations or energy crops) can eliminate or fragment habitats. Conversely,
if degraded land is used, and a diversity of tree species and ages are
maintained, biodiversity can be enhanced.
Traditional Biomass
Harvesting
Disturbance of natural ecosystems where fuelwood harvesting and charcoal
production activities encroach upon previously pristine woodlands and
forests.
Hydropower Projects
Flooding of areas behind dams destroys existing habitats. Building and
operation of dams can result in soil loss and siltation of rivers and estuaries,
disrupt fish populations, and deprive downstream ecosystems of nutrient
flow.
Fossil Fuel Exploration
and Extraction
Exploration for and extraction of fuels can result in large-scale loss of
habitats as soils and vegetation are stripped away to provide access to the
fuel resources. Emissions from the operation of fuel production facilities
such as contaminated drainage waters from mines and spills from test and
operating oil wells also have the potential to reduce biodiversity.
Fuel Combustion
Pollutants emitted during fuel combustion can disrupt habitats through many
mechanisms, including climate change, acid deposition, local air pollution,
and release of toxic compounds and metals.
Transportation and
Transmission Projects
Construction of electric transmission lines, pipelines, roads, and other energy
transport modes can fragment animal and plant habitats, import pollution,
and lead to increase human settlement, which in turn can place greater
stress on plants and animals in the area.
Central-station solar
plants
Land must be cleared and kept clear of larger plants in order to install and
maintain solar collectors. Collectors also keep sunlight from reaching the
ground, preventing or reducing plant growth.
2.3 Regional Issues
The distinction between global and regional issues is obviously difficult to precisely define. For
instance, land degradation, the first of the regional issues discussed below, is intimately related to
reductions in biodiversity, a global issue in our taxonomy.
In this section, we present overviews of a group of environmental issues -- land and water use and
degradation, ocean contamination, mobilization of toxic contaminants, acid deposition, and radioactive
24
A Guide to Environmental Analysis For Energy Planners
waste -- that are often characterized by regional impacts occurring over a wide area, potentially at a great
distance from the location where the responsible energy technologies are used.
Land and Water Use and Degradation
Land degradation -- soil erosion, deforestation, desertification, and so on -- is arguably the single
most visible and immediate environmental concern in many developing countries. It has many forms and
many causes. It is also a somewhat controversial issue. Where some may view forest clearing as habitatthreatening, climate-altering deforestation, others may see it as an opportunity to exploit natural resources
or expand agricultural productivity. In addition, the question of reversibility is an essential one. Land
cleared for charcoal production and/or other purposes may or may not regenerate; "deforestation" may or
may not be permanent, and soil may or may not be degraded in the process. As described below, local
factors such as post-harvest land management and soil and climate characteristics are important
determinants of the fate of cleared land.
A recent UNEP study provides what is perhaps the most extensive global survey and assessment of
trends and causes of soil degradation. (Oldeman, van Engelen, and Pulles, 1990) Soil degradation is
defined in that study as "a process that describes human-induced phenomena which lower the current
and/or future capacity of the soil to support human life". (L.R. Oldeman, as cited in World Resources
Institute, 1992, p.112-3) Although we might use a broader definition for land degradation, one that
includes reduced ability to support healthy ecosystems and reduced aesthetic value, the results of the UNEP
study provide an interesting comparison across causes and regions. The study found that the largest single
global cause of soil degradation to be overgrazing, accounting for 35% of the global total, as shown in
Table 2.3 below. Woodfuel overexploitation, on the other hand, is estimated to account for only 7% of
global degraded area, with greater relative importance in Africa (13%) and Central America (18%) than in
other regions.
Table 2.3:
Levels and Causes of Soil Degradation by Region
Africa
Europe
Asia
Oceania
North America
Central America
South America
World
Total Degraded
Area (Million ha)
[% of Vegetated
Area]
494 [22%]
219 [23%]
747 [20%]
103 [13%]
96 [5%]
63 [25%]
243 [14%]
1964 [17%]
Woodfuel
Overexploitation
Land
Conversion
& Logging
Overgrazing
Agricultural
Activity
Industrialization
13%
-6%
--18%
5%
7%
14%
38%
40%
12%
4%
22%
41%
30%
49%
23%
26%
80%
30%
15%
28%
35%
24%
29%
27%
8%
66%
45%
26%
28%
-9%
-----1%
Source: Oldeman, van Engelen, and Pulles, 1990 as cited in World Resources Institute, 1992.
These data concur with the general understanding that woodfuel use is only one, often less
important, of many factors that can result in soil and/or land degradation. Similarly, the collection of
subsistence levels of woodfuels is only one of several processes that contribute to the clearing of forested
lands. Commercial logging and land clearing for agricultural expansion are often the major contributors to
deforestation. Furthermore, despite indicative aggregate figures, there are no generalizable results or
relationships that can be used to estimate the role of woodfuel harvesting on land and soil degradation, or
Major Environmental Problems Associated with Energy Activities
25
on deforestation. While woodfuel scarcity and land degradation problems are often of regional importance,
they tend to be dependent on highly localized conditions.
As noted above, another major potential contributor to water and land degradation is water
impoundment for hydroelectric and other purposes. High-head hydroelectric dams can flood large areas,
forcing resettlement of local human populations, and displacing or killing animal and plant populations.
By their nature, hydroelectric dams also change the timing and magnitude of water flows. In larger
rivers, this can affect downstream and upstream fish populations, the availability of water to sustain
aquatic ecosystems, agriculture, and mariculture (e.g. shellfish harvesting), to recharge ground water, and
to provide for domestic needs. In addition to changing the quantity of water available, the quality of water
can also suffer. Lower water flows can cause an increase in the concentrations of salts, toxic metals,
fertilizers, pesticides, and herbicides. “Hydro” projects can also change the amount and timing of sediment
flow in rivers, potentially affecting the fertility of farmlands in downstream areas and/or changing flood
patterns. Operation of hydroelectric facilities sometimes involves rapid fluctuation of the amount of water
released, as the demands for electricity by consumers change over a day, week, or year. These fluctuations
can cause rapid changes in water levels downstream and in the reservoir behind the dam, changes that are
disruptive to ecosystems and human activities alike. The large impoundments (lakes) behind hydroelectric
dams also may change regional weather patterns by altering the extent, timing and location of evaporation
of water. Box 2.4 summarizes these and other impacts of the construction and operation of hydroelectric
facilities.
Large-scale use of biomass energy can also have regional impacts on water and land use. If large
tracts of forest lands are cleared to plant fuel crops or for direct use as fuel, erosion could result, affecting
ecosystems and human activities downstream. Intensive irrigation of biomass crops may deplete surfaceand ground-waters, leaving less water of potentially poorer quality for areas downstream. This may even
happen in the absence of vegetation, if biomass crops that are particularly adept at tapping the water table
replace natural vegetation that transpires21 less water to the atmosphere. Intensive use of fertilizers,
herbicides and pesticides in biomass production can also affect downstream water quality as these
chemicals are carried away with runoff or eroded soil, or leach into ground water.
Other energy resources and technologies also have land and water use impacts. Oil and gas
production sites can disturb sensitive ecosystems, consume water resources, and produce drilling wastes
and localized oil spills that can contaminate surface and ground waters. (See section on Ocean
Contamination below.) Coal mining, particularly surface or strip mining, can degrade large areas.
Electric production facilities, particularly those using wind and solar resources, can also require significant
land area.
Land use comparisons among energy options should distinguish between land that is “occupied”
and the land that is actually “used” or devoted solely to energy production. In the case of wind energy
“farms”, and some solar and biomass facilities, a large land area may be occupied relatively sparsely with
wind turbines or solar panels and the remaining area is available for other purposes such as grazing
21 "Transpiration" or "Evapotranspiration" is the process whereby growing plants use water for growth, and in so doing, move
water from the soil to the air. Water taken up by the roots of plants passes through the plant stems and branches and
evaporates from leaf surfaces. Different types of plants transpire different amounts of water for each kilogram of biomass
produced.
26
A Guide to Environmental Analysis For Energy Planners
BOX 2.4:
POTENTIAL ENVIRONMENTAL AND SOCIAL IMPACTS OF
HYDROELECTRIC POWER DEVELOPMENT AND OPERATION
SOURCE OF IMPACT
DESCRIPTION
Plant Construction
Direct environmental impacts include those caused by water diversion,
drilling, slope alteration, reservoir preparation, and building of infrastructure
(roads, dwellings, sanitary facilities) for the project workforce. Indirect
Impacts include the impacts on the surrounding area of an often large group
of construction workers, their families, and others, including deforestation,
the emergence of shanty towns, sanitation problems, and the exacerbation of
urban and rural poverty.
Land Inundation and
Reservoir Filling
As noted in the text, inundation of reservoir areas displaces local
populations, especially as people tend more often to live in rural valleys
where water and rich soil are often found. Resettlement of populations may
be disruptive to the way of life of those being resettled and to existing
residents of the resettlement area. Acquiring land for the reservoir and
providing for resettlement can also be significant economic concerns. The
loss of floodplains removes a crucial area of interaction between riverine and
terrestrial ecosystems. Filling or emptying reservoirs has been known to
cause or increase seismic activity (earthquakes) in the region of the hydro
facility. If biomass (especially small plants, leaves, and twigs) are not
removed from the reservoir area before filling, its decomposition can affect
water quality.
Changes in Water
Quality, Sedimentation,
and Ecosystems
The existence of the impoundment changes the flow of oxygen, chemical
nutrients, and soil particles normally carried downstream by the river. Water
temperature can also be affected. Ecosystem changes caused by dams
include their impact as barriers to fish migration, killing of fish that pass
through hydroelectric turbines, and the loss of fish species that must have
flowing water to survive. These changes affect natural ecosystems and
agricultural areas downstream. Disturbance of ecosystems may create
breeding grounds for water-borne pathogens. In the reservoir itself, lack of
mixing can create stratified (layered) areas of water, including layers with
little or no oxygen where biomass (including biomass remaining in the
reservoir at the time of filling) decomposes to methane, a greenhouse gas.
Anoxic (no oxygen) conditions also may help to release heavy metals and
other pollutants brought by the river from upstream areas. Sediment carried
by the river when free-flowing builds up in the reservoir, often reducing the
water and electricity generating capacity of the plant.
Public Health
Major human diseases associated with water resource development include
malaria, shistosomiasis, and lymphatic filariasis, which together afflict over
half a billion people in developing countries. Reservoirs provide breeding
grounds for the organisms (such as mosquitoes) that act as hosts to these
pathogens.
Source: J.R. Moreira and A.D. Poole, Chapter 2, “Hydropower and Its Constraints” in Johansson et al,
1993.
Major Environmental Problems Associated with Energy Activities
27
or natural habitat (as in well-designed biomass plantations). Figure 2.4 below provides a comparison of
the land occupied and used for coal, wind, and solar electricity production in California. When the land
used for resource extraction (e.g. coal mining) is included, and the land used is distinguished from land
occupied, the land use for coal and solar electricity appear comparable, while wind is lower.
Figure 2.4:
Land Used for Electricity Generation in California22
12
10
Area Occupied
hectares/MW
8
Area Used
6
4
2
0
SolarThermal
(parabolic
trough)
Coal
(includes
mining)
SolarThermal
(central
receiver)
Solar PV
(dense area)
Wind
Solar PV
(desert)
2.3.1
2.3.2 Acid Deposition
Acid deposition results when nitrogen and sulfur oxides ("NOx" and "SOx") react in the atmosphere
with oxygen and water droplets to form nitric and sulfuric acids (HNO3 and H2SO4). As the water droplets
condense, they fall as rain, snow, or fog, hence the common name "Acid Rain". We should note that while
acid rain is the most frequently discussed pathway for these compounds to return to earth, nitrates and
sulfate ions23 (NO3- and SO42-) also can combine with positive ions or adhere to the surface of particles in
the atmosphere, sometimes falling to earth in a dry form (“dry deposition”). SOx and NOx can also directly
adhere to soil or plant surfaces, eventually reacting with water and oxygen to form acids. As a
consequence, the terms "Acid Rain" and "Acid Precipitation" are somewhat incomplete--though more
common -- terms for the broader phenomenon of acid deposition, the term we use most frequently here.
The standard measure of acidity is the pH scale. pH is equal to the base-10 logarithm of the
concentration of hydrogen ions (H+), and is given on a scale of 0 to 14, with low pHs being indicative of
22 Based on Gipe, 1991, p.764. For comparison, Pasqualetti and Muller, 1984, report a land-use requirement of 7-13 acres (3-
5 hectares) per MW for mid-Western US opencast coal mines.
23 Ions are electrically charged elements of molecules. Negatively charged elements or molecules (like the sulfate and nitrate
ions) are called anions, and positively charged entities are called cations. Anions and cations combine to neutralize each others
charge and yield salts, such as the common table salt, NaCl, which is made up of a positively-charged sodium atom (Na+) and a
negatively-charge chloride ion (Cl-).
28
A Guide to Environmental Analysis For Energy Planners
highly acid solutions (e.g. vinegar), and high pH's being indicative of highly alkaline (or basic) solutions
(such as lye). Neutral pH, the pH of distilled water, is 7.0, and physiological pHs, that is, the pHs most
commonly found in plant and animal cells, are typically (but not always) between 6 and 8. In the
atmosphere, water reacts with CO2 to form carbonic acid (H2CO3), a weak acid, and as a consequence the
pH of rain and snow in the absence of all pollutants would be about 5.6. Precipitation with a pH lower
than this level is considered acid precipitation. Remember that because pH is measured on a logarithmic
scale, small changes in pH can mean relatively large changes in acidity. Precipitation with a pH of 4, for
example, is 10 times as acid as rain of pH 5.
The effects of acid rain vary considerably with the vegetation, soil types, and weather conditions in
a given area. Under some conditions, the addition of sulfate and nitrate to the soil helps replace lost
nutrients, and aids plant growth. In other instances, however, acid deposition can cause lakes and streams
to become acid, damage trees and other plants, damage man-made structures, and help to mobilize toxic
compounds naturally present in soil and rocks. Acid rain has been implicated in the death of fish and other
aquatic life in otherwise pristine lakes in the northeast United States, southeast Canada, and Scandinavia.
Lakes and soils with minimal buffering capacity (the ability to maintain pH in response to the addition of
acids), such as many of those found in these areas, are particularly susceptible to acid rain. The lowered
pHs in some North American and Scandinavian lakes has resulted in loss of and/or shifts in species
composition of the phytoplankton (including algae) that are the base of the aquatic food chain, and damage
-- direct and indirect -- to aquatic invertebrates (e.g. insects and small crustaceans), amphibians, and fish.
The gradual die-off of forests in Germany, Sweden, and other areas has also been attributed to the effects
of acid deposition. Plants are affected by acid rain in several ways, including direct erosion of cellular
structures in leaves, interference with cell processes and the uptake of gases (including CO2) from the
atmosphere, alteration of soil chemistry and the activity of bacteria and other microorganisms in soil,
interference with plant reproduction, and weakening of plants' susceptibility to disease and pests.
Buildings and other structures, including many ancient cultural landmarks, are being degraded by acid rain,
particularly those structures made of minerals, such as limestone, that are more soluble in more acidic
solutions. In soils with limited buffering capacity, the acidified water flowing through the soil can dissolve
and mobilize potentially toxic minerals, such as aluminum, leading to elevated concentrations in streams
and lakes. A nutrient in small quantities, aluminum can become toxic to fish and other organisms at the
higher concentrations found in acidified watersheds24.
While natural sources account for a significant, though uncertain, fraction of the atmospheric
sulfur and nitrogen oxides that are the precursors of acid deposition, human sources appear to be the major
cause of recent declining trends in the pH of rainfall. While some industrial sources of emissions,
particularly the smelting of metal, are important sources of sulfur oxides, the energy sector accounts for a
large fraction of these emissions. Sulfur oxides are produced during combustion of coal, which contains
varying amounts (about 0.5 to 5 or more percent) of sulfur, and during combustion of fuel oil, particularly
the heavier grades. These fuels are most commonly used in large industrial facilities and in electric power
generation. Nitrogen oxides are produced at varying rates by all types of fossil and biomass fuel
combustion; the nitrogen in the NOx produced during combustion is derived both from nitrogen in the fuel
and from the molecular nitrogen (N2) that makes up nearly four-fifths of the air we breathe. Gasolinepowered autos and trucks are major emitters of NOx.
Though acid deposition can be a local phenomenon, particularly in urban areas and in areas near a
large point source of emissions, the extent to which acid gases are carried by prevailing weather patterns
makes acid rain a truly regional issue, one that frequently crosses national boundaries. For example, many
24 A watershed is the area around a body of water that catches the rain and snow that feed into it.
Major Environmental Problems Associated with Energy Activities
29
of the acidified lakes in Eastern North America are hundreds of kilometers from major sources of
emissions. Likewise, emissions from as far away as the United Kingdom have contributed to acid rain and
forest decline in Scandinavia. Automobile use in Southern California is probably a major contributor to
low-pH rain and snow in the Colorado Rockies, well over 1000 kilometers away.
2.3.3 Mobilization of Toxic Contaminants & Bioconcentration
Emissions to the air and water from energy technologies can also lead to the mobilization of toxic
contaminants that, in turn, can have far-reaching impacts. Once introduced into the environment, a toxic
material can be transported by a variety of physical means (for example, wind, groundwater flow) to
sensitive organisms, or can reach those organisms less directly through bioconcentration in the food chain.
Table 2.4 presents some of the pollutants that can be mobilized by human activities, and provides an
indication of how human activities contribute to the level of those pollutants in the biosphere.
One example is the lead used in a performance-enhancing additive in automotive fuels. When
"leaded" fuels are burned, the lead that goes out the tailpipe (typically as a compound called tetraethyl lead,
which is more toxic than elemental lead metal) can end up, blown by prevailing winds or carried in rivers,
in the ocean, where it may have several effects. Since lead (and other toxic metals, such as mercury and
cadmium, which are emitted by energy technologies such as coal combustion and oil refining) is
concentrated in the ocean food chain, the danger of chronic or acute poisoning is increased for the larger
animals in the chain (including humans). As of the mid-1970's, it was estimated that the average global
lead concentration in the open ocean had increased several-fold since the introduction of leaded gasolines
(Ehrlich, Ehrlich, and Holdren, 1977).
The food chain denotes the linkage between predators and prey, producers and consumers. Each
food chain is founded on a plant or collection of plants called the "primary producer(s)". The primary
producer takes in solar energy, carbon dioxide, water, and nutrients, and produces plant biomass. These
plants are then eaten by animals or microbes, called the primary consumers, which may be eaten by other
animals, and so on up to the "top carnivore", the animal that is at the top of the food chain. Some natural
or managed food chains may be very short, e.g. grass is eaten by cattle which are eaten by people. Others
may be much longer, as in the ocean where phytoplankton (algae and other microscopic plants that float
free near the surface waters) are eaten by zooplankton (tiny animals that float along with the
phytoplankton), which are in turn eaten by tiny fish, which are eaten by larger fish and so on up to a top
carnivore such as a shark or human. No matter what the length of the food chain, conservation of energy
dictates that there is less biomass -- actually on the order of ten-fold less -- at each level of the chain. This
reduction in biomass, which can be several orders of magnitude for a longer food chain (i.e., it might take
10 tonnes of algae to ultimately produce 1 kg of shark) is important because some pollutants are retained in
the bodies of the organisms that take them in, then passed on to the organisms higher up the food chain.
Thus a compound that is present at level too low to cause biological problems, say one part per million
(ppm) in a primary producer, may be a thousand-fold more concentrated in a top carnivore, and may at that
level be quite toxic.
30
A Guide to Environmental Analysis For Energy Planners
Table 2.4:
Human Disruption and Mobilization of Pollutants: Global Estimates
(Adapted from Holdren, 1990)
Affected
Quantity
Lead (Pb) Flow
Natural
Baseline
Human
Disruption Index
15
Mercury (Hg)
Flow
Cadmium (Cd)
Flow
25,000
tons/year
25,000
tons/year
1,000
tons/year
Oil Flow to
Oceans
250,000
tons/year
13
Sulfur Dioxide
(SO2) Flow
Carbon
Monoxide (CO)
Flow
160,000
tons/year
500 million
tons/year
>1
Nitrogen Oxide
(NOx) Flow
Particle Flow
40 million
tons N/year
500,000
tons/year
1
Cumulative Soil
Degradation
not
applicable
.7
8
1.4
.6
17% of global
vegetated area
Sources of Human Disruption
60% fossil fuel combustion
40% metal processing, manufacturing, refuse burning
20% fossil fuel combustion
80% metal processing, manufacturing, refuse burning
10% fossil fuel combustion
70% metal processing, manufacturing, refuse burning
20% traditional fuel combustion; agricultural burning
50% marine oil transport (spills, routine operation)
40% municipal and industrial wastes and runoff
10% atmospheric emissions
90% fossil fuel combustion
10% metal smelting, sulfuric acid production, etc.
30% fossil fuel combustion
25% oxidation of anthropogenic methane
25% forest clearing; 15% savanna burning
10% from wood burning, other HC oxidation
75% fossil fuel combustion
25% fertilizers, biomass burning, industrial processes
35% fossil fuel combustion
10% traditional fuel combustion
40% agricultural burning, wheat handling
15% smelting, land clearing, refuse burning
woodfuel harvesting, overgrazing
Sources: Adapted from Holdren 1990; Additional Data from UNEP, 1989 and Katsouros, 1992.
The classic example of a bioconcentrated toxin is DDT25, which was used extensively as a
pesticide in the 1950's and 1960's. This chemical was found at very high concentrations in the blood and
eggs of large birds, including the brown pelican (Ehrlich et al, 1977) and other top carnivores, often
causing failure in reproduction and/or other effects. In the energy sector, other potentially bioconcentrated
toxins include pesticides and herbicides sometimes used on biomass crops or to maintain road, power line,
or pipeline right-of-ways, and compounds or metals that are produced, discarded and/or released during
petroleum refining, oil and gas exploration, and geothermal power generation.
2.3.4 Ocean Contamination
The most visible and prevalent example of direct spillage of energy products into oceans is that of
"oil spills". Crude oil and refined products spill during routine operation of offshore oil rigs, from oil
tanker filling and off-loading operations, during the cleaning of tankers, as spillage from other (non-tanker)
25 DDT is the chlorinated hydrocarbon dichlorodiphenyl trichloroethane.
Major Environmental Problems Associated with Energy Activities
31
ships that use petroleum fuels, and as a result of leakage from undersea pipelines, as well as during less
frequent but better-publicized oil tanker accidents and "blowouts26" at offshore oil platforms.
These spills are toxic to many forms of marine life, as well as fouling beaches and affecting other
ecosystems and man-made installations along the shoreline. Oil floating on the ocean’s surface can coat
marine birds, making them unable to fly, reducing the insulating properties of their feathers (so that they
can no longer stay warm), and usually eventually killing them. Birds can ingest oil when they try and
preen it out of their feathers, and developing embryos inside eggs can be killed if oil gets on the egg. Oil
spills also disrupt the food chain by killing phytoplankton and zooplankton27 at or near the oceans surface.
Toxic and carcinogenic (cancer-causing) compounds in oil products can cause death and illness in these
organisms or they can become bioconcentrated (as discussed above) in the food chain. Heavier oil products,
and the heavier fraction of crude oils, sink to the bottom, where they can coat shellfish beds, making
shellfish and other invertebrates inedible. Damage from oil spills may persist for many years, as
compounds contained in oils can remain both in the bodies of organisms and in marine sediments. Oil
spills can be spread rapidly by tides, currents, and winds, making them a regional as well as local threat.
Table 2.5:
Sources of Petroleum Hydrocarbons in the Marine Environment
(Millions of Tonnes Annually)
Source
Natural Sources
Atmospheric Pollution
Marine Transportation
Offshore Petroleum Production
Municipal and Industrial Wastes and Runoff
Total
Probable Range
0.025 - 2.5
0.05 - 0.5
1.00 - 2.60
0.04 - 0.06
0.585 - 3.21
1.7 - 8.8
Best Estimate
0.25
0.3
1.45
0.05
1.18
3.2
Source: M.H. Katsouros, Chapter 5 in Hollander, 1992.
Several other ocean/sea environmental impacts are related to existing or possible future energy
development activities. By changing the timing and amount of fresh water and sediment flows that reach
the ocean, hydroelectric projects on major rivers can affect ocean ecosystems. Much of the total
production of plant and animal biomass in the ocean takes place near land, and many animals live at least
part of their lives in or near fresh water or in the estuaries where fresh water from rivers mixes with the salt
waters of the oceans. Changing the timing and amount of fresh water can change environments at the
ocean's edge sufficiently as to affect the breeding and growth of the organisms there, which can have an
impact on the marine ecosystem in the entire region. Too little sediment flow can reduce the fertility of the
ocean by reducing the input of needed inputs from the land. Too much sediment flow, on the other hand,
can increase the turbidity (or murkiness) of water, resulting in reduced photosynthesis and productivity.
Excess sediments can also bury key marine habitats, such as shellfish beds.
26 A blowout occurs when the wellhead where the flow of oil from a well is controlled fails catastrophically, allowing oil,
driven by high gas and/or liquid pressures in the well, to flow out of the well and into the surrounding environment.
27 Phytoplankton is a name used to denote the class of microscopic-to-barely-visible aquatic plants that are the base of much of
the ocean's food chain. Phytoplankton include marine algae, diatoms, and other photosynthetic organisms. Zooplankton are
the micrometer-to-millimeter-size animals that, like the phytoplankton they feed on, float along near the surface of the ocean.
Zooplankton include the larval and juvenile (young) stages of a number of commercially and biologically important organisms,
such as crustaceans (e.g. shrimp and crab) and mollusks (shellfish). Zooplankton in turn serve as food for small fish and other
animals.
32
A Guide to Environmental Analysis For Energy Planners
Several proposed ways of capturing energy from the oceans, typically as electric power, have been
discussed and investigated in recent decades. These options, including ocean thermal energy conversion
(OTEC), and generating electricity from tidal power, wave power, and ocean currents, may have regional
as well as local impacts. OTEC, in which large quantities of cold deep ocean water are brought to the
surface (power is generated by taking advantage of the difference in temperature between this water and
warmer surface waters) increases the supply of nutrients to marine ecosystems near the surface, which can
change the distribution of marine biomass in the region. Tidal power stations (in their simplest form)
employ a dam that can be open and shut across the mouth of a bay. Sea water admitted at high tide is
released through a turbine at low tide to generate electricity. Their operation changes the patterns of water
supply to the bay and surrounding waters, potentially with many of the same impacts on marine life as
land-based hydroelectric systems have on freshwater ecosystems. Systems to capture energy from waves
or ocean currents are unlikely to have regional impacts if deployed on a small scale, but could potentially
influence fish and marine mammal migration patterns, shipping, or the circulation of ocean currents if they
are used extensively. Wide use of any of these ocean-energy technologies is unlikely within the next few
decades.
2.3.5 Radioactivity and Radioactive Wastes
Nuclear energy, from fission, and perhaps in the future from fusion28, has tremendous theoretical
potential as an energy source, but social, economic, institutional, and environmental concerns have slowed
its development significantly over the past decade. As of 1989, twenty-three countries used nuclear fission
to generate electricity, the combined amount accounting for slightly more than two percent of total global
commercial energy production (World Resources Institute, 1992; Table 21.1). To date, with the obvious
exceptions of nuclear weapon detonations and the accident at the Chernobyl power plant in April 1986,
exposures of the public and environment to radioactive pollution have been limited. Nevertheless, as a
result of Chernobyl and other near catastrophes such as the 1979 accident at Three Mile Island in the
United States, concerns over the safe operation of nuclear power plants persist29. Critics also contend that
waste storage and weapons proliferation problems have not been, and perhaps cannot be, adequately
addressed. On the other hand, advocates promote nuclear power as a clean energy choice for the future.
Radioactive materials undergo spontaneous transformations of their atomic nuclei. The number of
transformations occurring per unit of time is a measure of radioactivity. The common unit for radioactivity
is the curie (Ci), representing approximately 37 billion nuclear transformations per second. Nuclei
undergoing transformations emit energy (radiation) in the form of alpha particles, beta particles, gamma
rays, or individual neutrons. Alpha particles are massive and unable to penetrate human skin. Therefore
they are dangerous -- and are capable of causing great damage -- only if they are emitted inside the human
body, after ingestion or inhalation. Plutonium-239, for example, is a powerful emitter of alpha particles.
Beta particles are much lighter and more capable of penetrating barriers. Like alpha particles, they are
most harmful if emitted internally, but externally-emitted beta particles can also be dangerous. Gamma
rays and neutrons are capable of traveling hundreds of meters and penetrating solid walls.
Radioactivity and the effects of ionizing radiation have been so well studied that radiation, some
suggest (Ehrlich, Ehrlich and Holdren 1977), may be the best understood of the major pollutant categories.
28 Fission refers to the process in which the nuclei of large atoms, e.g. Uranium, are split to form smaller atoms, liberating
energy (fast-moving particles and electromagnetic radiation) in the process. Fusion occurs when the nuclei of smaller atoms,
such as hydrogen, are forced together to form larger atoms, which also releases energy.
29For a description of the events, and potential impacts of the accidents at Three Mile Island and Chernobyl see Chapter 6,
"Nuclear Power" by Hohenemser, Goble and Slovic, in Hollander (1992).
Major Environmental Problems Associated with Energy Activities
33
The available information on radiation effects may still, however, be inadequate, since significant
uncertainties remain.
Exposure to radioactivity is typically measured in rems or sieverts (Sv)30. Rems equal rads, a
measure of the amount of energy deposited per unit mass of absorbing material, multiplied by a factor
accounting for the effectiveness of the deposited energy in doing damage. Doses of radiation in the range
of 100 rems to more than 1000 rems could be experienced as the result of the detonation of a nuclear
weapon, or during a catastrophic accident at a nuclear power station or fuel reprocessing plant. These
levels of exposure are likely to lead to acute illness or death within hours to weeks after the exposure. The
lethal dose of radiation expected to kill 50 percent of the exposed population within sixty days of the
exposure is generally assumed to be 250 to 450 rem. Doses from naturally-occurring background sources
of radiation in the United States range from 100 to 250 millirems/person/year31. Common exposure
standards are 5 rems/year whole body exposure for workers in the nuclear industry, 500 millirem/year to
individual members of the general public, and 170 millirem/year as an average exposure for large
populations. Statistical analyses have shown links between increased, non-acute radiation exposures and
increased cancer rates, genetic defects, prenatal problems, fertility problems, and cataracts of the eye
(Doull et al, 1980). The National Academy of Sciences estimated that increasing the background exposure
level in the United States by 100 millirem would result in 3000 to 4000 additional cancer deaths per year
and an equal number of additional non-fatal cancers (Ehrlich, Ehrlich, Holdren 1977).
Exposures to radioactivity from the routine operation of nuclear power stations are relatively
minor. Releases of tritium and krypton gas during the reprocessing of nuclear fuels are the largest routine
emission, and these represent only small additions to natural background radiation levels. More serious
environmental questions are related to the sustained management of nuclear wastes, the possible
proliferation of nuclear weapons, and the prevention of catastrophic radiation releases from reactors and
reprocessing plants. The inventory of a large nuclear reactor's long lived radioactivity is more than 1,000
times that of the atom bomb dropped on Hiroshima. Radioactive wastes must be safely managed for long
periods of time, tens of thousands of years for materials with long half-lives. Creating a hazard that is a
threat so far into the future poses an ethical question of inter-generational responsibility. No proposals for
the long-term disposal of high level nuclear wastes have been able to overcome political and technical
objections, and the question of what to do with nuclear wastes remains unresolved.
Another consideration in weighing the attributes and problems of nuclear energy is the potential for nuclear
weapons proliferation, that is, the potential for nuclear materials from power reactors to be diverted for
non-peaceful uses. All fission reactors produce materials suitable for making nuclear weapons. The
amount of fissile material32 required to make a weapon depends upon the material's critical mass. For
plutonium-239 the critical mass lies in the range of 4 to 8 kilograms, and for uranium-235 the high end of
the range is only 25 kilograms. (Ehrlich, Ehrlich, and Holdren, 1977). Even the most meticulous national
or international accounting and security measures cannot insure that amounts sufficient for weapons
building do not go missing. Even smaller amounts of highly toxic radioactive materials such as plutonium239 could be used to, for example, poison the water supply of a major city.
The promise of nuclear energy has been offset by the specter of potential large-scale environmental
disasters. Large-scale radiation releases, eventually resulting in tens, even hundreds of thousands of
deaths, widespread property loss and ecosystem contamination are improbable, but not impossible. More
30 1 rem = 0.01 Sv.
31 Recall that one millirem is one thousandth of a rem.
32 Material that can undergo fission reactions.
34
A Guide to Environmental Analysis For Energy Planners
than with other energy technologies, assessing the environmental impacts of nuclear energy hinges upon
estimating the probabilities and acceptability of rare and catastrophic events (see under Accidents below).
As a consequence, debate on this issue is likely to continue.
2.4 Local Issues
Some or all of the issues discussed above can, it could be reasonably argued, be considered local as
well as regional in scale, depending on the magnitude of the specific disturbance caused by the energy
system evaluated. What follows is a discussion of environmental issues whose effects are mostly on the
local level, that is, within the area where the fuel-consuming device or energy supply technology is located.
2.4.1 Urban Air Pollution
Power plants that burn fossil or biomass fuels emit pollutants that, if not properly controlled, can
cause or exacerbate health (especially respiratory) and aesthetic impacts in the locale of the plant. These
pollutants include particulate emissions, , carbon monoxide, hydrocarbons, and others. Emissions vary
significantly with the type of power plant and the fuel used. Geothermal plants can emit hydrogen sulfide,
a noxious and, in high enough concentrations, toxic gas.
The production, distribution and combustion of fossil fuels -- particularly combustion in motor
vehicles -- emits carbon monoxide, NOx, SOx, hydrocarbons, and other compounds In high enough
concentrations, these molecules can react with each other, additional compounds already present in the
atmosphere, and sunlight to yield photochemical smog. If sufficiently severe, smog can be a hazard to
human health, livestock, and natural ecosystems, as well as damaging buildings or other structures
(Ehrlich, Ehrlich, and Holdren, 1977; Freedman, 1989; USEPA, 1985).
Compounds containing lead have until recently been routinely added to motor fuels to enhance
engine performance. When these fuels are burned, lead is emitted, and can be taken up by both plants and
animals, including humans, from the air or in food and water. Lead poisoning -- which can impair the
function of the muscular, brain, circulatory, and digestive systems -- results when level of lead in the blood
rise above a threshold level, but lower levels of lead may also cause physiological problems. The process
of removing lead from motor fuels is underway, but not yet complete (Ehrlich, Ehrlich, and Holdren, 1977).
Combustion of wood in wood stoves releases particulate matter, carbon monoxide, hydrocarbons,
and other pollutants. At most times of the year this does not cause serious problems in the rural areas
where wood is typically burned (especially in developed countries), but under atmospheric conditions
known as temperature inversions, which occur relatively frequently in the winter in some temperate locales,
wood smoke can be retained within small valleys, allowing pollutants to build up to levels that can
exacerbate or cause respiratory problems (Ehrlich, Ehrlich, and Holdren, 1977; California Air Resources
Board, 1990).
2.4.2 Indoor Air Pollution
While the concept of air pollution is often associated with smokestacks, automobiles, and smoggy
urban environments, there is evidence to suggest that indoor air pollution may also have significant health
impacts. Indoor fuel combustion can create elevated concentrations of carbon monoxide, carbon dioxide,
oxides of sulfur and nitrogen, particulate matter and polycyclic aromatic hydrocarbons. Globally, biomass
fuels used for cooking, lighting and heating are the most common source for these emissions. Over half of
Major Environmental Problems Associated with Energy Activities
35
the world's population depends upon wood fuels, crop residues, or dung to meet their daily cooking energy
requirements (OTA, 1991, p.51).
The type and level of emissions depend on several factors: fuel type, the design of the end-use
device, and the nature of the combustion. Smith (1987) notes that while biomass fuels can be burned with
minimal smoke production and with the release of few toxic contaminants, under normal operating
conditions household size stoves emit a wide range of the pollutants listed above. The resulting indoor
pollutant concentrations and human exposures depend on additional factors such as dwelling architecture,
indoor/outdoor air exchange rate, and the duration of an individual's exposure to the emission source. Due
to the extensive use of biomass fuels and the close proximity of human "receptors" -- particularly women
and children -- to the emission sources, the resulting pollutant "doses" can be quite high. Smith (1987)
calculates that in India, a ton of particulates emitted by household biomass stoves may produce over 500
times the combined human dose of a ton of particulates emitted by a coal-fired power plant.
In general, biomass fuel use under enclosed conditions can be expected to result in high emissions
of and human exposures to CO, particulates and hydrocarbons, and there is empirical evidence to validate
this expectation (Ellegard and Egneus 1992; Smith 1987). However, as illustrated in Table 2.5, the
evidence of direct relationships between increased exposures and negative health impacts is more
ambiguous.
Table 2.6:
Direct Evidence of Health Impacts of Domestic Biofuel Smoke Exposure
(from Smith, 1987)
Health Effect:
Chronic Obstructive Lung
Disease
Cancer
Acute Respiratory
Infection
Low Birth Weight,
Cardiovascular Disease
------------------------------------- Study Location----------------------------------Africa
Papua New
India
China
Nepal
U.S./U.K.
Guinea
QA+
A+/Q-
A+/SQ±

A+/AQ-
A+/SQ±

A+

A+/Q
SQ+/Q+

AQ+/Q+
A+/AQ
Q±






Notes: + = Positive evidence, - = negative evidence, A = Anecdotal evidence, Q = Quantitative evidence,
SQ = Semiquantitative Evidence
Sources: Smith (1987; p.227), Ellegard and Egneus (1992).
Much of the evidence on the health effects of indoor air pollution is anecdotal or conflicting,
suggesting the need for further research. For two potentially important health categories, birth weight and
cardiovascular disease, no studies are available. The conflicting evidence is not surprising since studies of
direct health impacts must account for a number of factors, such as the delayed effects of chronic
exposures and their interaction with other health variables such as smoking, and diet.
In countries where biomass fuels are not widely used, indoor air pollution may still be a concern.
Emissions sources include improperly vented propane or natural gas cooking and heating appliances,
household chemicals, cigarettes, and radioactive Radon gas. Generally, the most effective approach to
controlling these hazards is to identify and minimize, or eliminate, the pollutant source. In the case of very
36
A Guide to Environmental Analysis For Energy Planners
tightly sealed houses, where adequate source control is not possible, the installation of air to air heat
exchangers can provide adequate ventilation while minimizing heat loss.
2.4.3 Surface and Ground Water Pollution
Water is an essential resource for all life, and yet freshwater resources are under intense and
increasing stress. Water is continuously in demand, and is required for agriculture, industry, and domestic
use. Often, at the same time, waterways serve as receptacles for the waste products of society. The
vulnerability of civilizations to water stress is perhaps partially masked by the hydrologic cycle, which
operates at a global scale to replenish and renew freshwater stores and sources. Even so, it is increasingly
apparent that the stewardship of water resources is not an item to be considered only in cases of acute
imbalance and distress, but that the issue deserves general and consistent attention. In comparison to other
stresses on freshwater resources -- including water use for irrigation, pollution via agricultural runoff, and
pollution from municipal sewage -- energy-related water use and pollution are often relatively minor, but
the impacts are far from negligible.
Water pollution can be classified into at least seven major categories:
1) Excess nutrients from sewage and soil erosion, which can cause algae blooms that eventually
deplete the oxygen content of the water;
2) Pathogens from sewage that spread disease;
3) Heavy metals and synthetic organic compounds from industry, mining, and agriculture;
4) Thermal pollution, which can alter the chemistry and structure of aquatic ecosystems;
5) Acidification;
6) Suspended and Dissolved Solids; and
7) Radioactive pollution.
Energy production and consumption are most closely associated with the last five types of
emissions. The mechanics and consequences of acidification and radioactive pollution were discussed
previously in the section on Regional Environmental Issues.
At coal mines or coal burning facilities, water can be polluted through the use of particular
technologies (such as coal washing) or when pollutants are carried in runoff or as leachates33 from tailings
and storage piles. Mine tailings34 often release contaminants that were previously bound in impermeable
rock formations. The quantity and type of contaminants released depends on a number of factors,
including the local geology, hydrology and coal type. Emissions from coal-mine tailings commonly
include beryllium, cadmium, copper and zinc. Metals released into ground and surface waters can be
bioconcentrated in food chains or can be ingested directly by humans and other organisms. The deposition
of air-borne SO2 and NOx leads to the acidification of lakes and streams, which can have significant
negative impacts on aquatic ecosystems (see discussion in section 2.2, above). If mine tailings contain
sulfur compounds, acid drainage from tailing piles that are exposed to water can contribute to the
acidification problem. Aluminum, cadmium, mercury and lead become more soluble as acidification
progresses, resulting in higher levels of mobilized metals being released to ground and surface waters.
33 Substances from piles of coal or mine tailings that dissolve in water flowing on and through the piles are called leachates,
having leached from the piles into the surface or groundwater.
34 Typically piles of crushed rock that remain after the mineral being mined (e.g. coal, iron, or gold) has been extracted from
the mined ore.
Major Environmental Problems Associated with Energy Activities
37
Ash piles at thermal power plants are another potential source for water pollutants. Leachate and
runoff from ash piles commonly contain heavy metals including arsenic, beryllium, cadmium, chromium,
copper, iron, lead, mercury, nickel and vanadium. The type of contaminants present in each situation
depend upon the fuel type, combustion method, and pollution control methods used. Residues from power
plant boilers can contaminate water used in maintenance operations (such as the cleaning out or “blowdown
of boilers) with the heavy metals listed above.
Leaking domestic, commercial, or industrial fuel storage tanks can contaminate surface or ground
water with gasoline, heating oil or other petroleum products. Drilling for oil can release brine deposits and
damage surrounding freshwater ecosystems. The negative environmental impacts of oil spills were
discussed above in the section on regional environmental issues. Water withdrawal for mine drainage can
cause saltwater intrusion into freshwater aquifers. Uranium mines and mills, fuel fabrication plants,
nuclear power plants, fuel reprocessing plants, and nuclear waste storage facilities all have the potential to
release radioactive materials to ground and surface waters.
Thermal power plants produce more heat than electric energy, and must dissipate this waste heat to
the environment. Large thermal and nuclear power plants generally withdraw surface water and evaporate
it in cooling towers, which release heat (and water vapor) to the atmosphere. In sensitive aquatic
ecosystems, this withdrawal of water may be of concern. The adverse effects of aquatic thermal pollution
include lowered dissolved oxygen levels in the water, stress on aquatic organisms, and potential changes in
species distribution, food chains and reproductive behaviors. Geothermal electricity generation plants
must reject much more heat per unit of electrical output than other fossil or nuclear fired power plants35.
The liquids produced from the exploitation of high-temperature geothermal reservoirs typically contain
large amounts of dissolved minerals that can pollute surface and ground waters if not properly treated.
Thermal pollution of ocean waters is also an environmental concern associated with the development of
ocean thermal energy conversion plants.
2.4.4 Solid and Hazardous Wastes
As urban areas throughout the world continue to grow rapidly, the disposal of solid wastes
becomes more and more problematic. Residents of industrial economies generate more refuse per capita
than do the residents of developing countries, but the waste management capabilities of many cities in
developing countries are seriously over-burdened. The portion of total solid wastes produced by the
energy sector is generally small, but it can include hazardous and radioactive materials that demand special
handling.
Energy-related solid wastes are primarily generated by mining and fuel combustion. The largest
two sources of such wastes in the United States are coal mining and coal burning power plants,
respectively. The mining of copper and other metals used in the transmission and distribution of electricity
also produces solid wastes. In the United States, about 100 million tons of coal refuse are produced
annually by coal cleaning, an amount equal to approximately 30% of the mass of the raw coal processed
(Murarka, 1987). Heavy metals tend to be associated with the heavy fraction of coal removed during
cleaning, and these metals therefore become concentrated in refuse piles. By 1978 approximately 3.5
billion tons of coal refuse had accumulated in the United States (ibid.). Refuse piles can contaminate
35 This is because geothermal plants start with a heat source (geothermal energy) that has a low temperature relative to the hot
gases from fuel combustion, and this low temperature limits the efficiency with which heat can be converted into electricity.
Lower efficiency translates into increased heat production per unit of electricity generated.
38
A Guide to Environmental Analysis For Energy Planners
ground or surface water via leaching or runoff (as noted above). They are also prone to spontaneous
combustion and therefore are possible sources of airborne emissions.
In the United States, over 90% of the electric utility industry's solid waste is produced from coalfired power plants, which produced approximately 75 million tons of solid wastes in 1983. This quantity
is slightly more than one percent of the total annual solid waste production in the United States (Murarka,
1987). Wastes produced in large volumes by coal-fired power plants are fly ash, bottom ash, boiler slag,
and wastes from flue (exhaust) gas emissions control systems. Fly ash leaves the combustion chamber
with the flue gases, while bottom ash is deposited at the bottom of the boiler. These types of ash are
primarily composed of the non-combustible materials (inorganic minerals) in the coal along with some
unburned organic matter. Ash from emissions control processes is typically a mixture of fly ash, the
pollutant controlled (often sulfur) and the substance used in the emission control system, such as calcium
from limestone. The concentration of trace constituents in ash depends upon the coal type. Historically,
15 to 25 percent of the solid waste tonnage generated by coal burning plants have been reused in various
applications. Examples of such applications for coal ash include its use as a constituent of cement used
for road and airport runway construction, as fill material, and as a constituent of other construction
materials (ibid.). Flue gas desulfurization wastes, one of a class of wastes resulting from emission control
technologies, have potential for reuse in the production of gypsum for wall boards. The amount of
material re-used depends upon a combination of technical and economic factors. The most common
disposal method for high volume ash is to transport it in a slurried or wet form to surface ponds. Dry
disposal in landfills is also used. The environmental hazards associated with the wet disposal -- "ponding"
-- of ash are primarily the leaching into water supplies of soluble metals such as lead, vanadium, cadmium
and cobalt. Fugitive dust can escape into the air from dry ash being transported to landfills. While
landfill sites generally require less land area and are easier to reclaim and restore than are ponding sites,
leaching and runoff can still be a problem at dry disposal sites.
Other sources of energy-related solid wastes are oil and natural gas drilling, oil fired power plants,
and the nuclear fuel cycle, although these are relatively minor (by weight) sources of solid wastes in
comparison to coal technologies (DOE, 1983). The disposal of radioactive wastes was discussed
separately earlier in this Chapter.
Solid wastes can also be used as an energy source. In more than fifteen countries energy is
recovered from the incineration of municipal solid wastes (WRI 1992; Table 21.4). The type and quantity
of pollutants emitted by waste incineration plants (with or without energy recovery) depends on factors
such as the composition of the waste materials, and the combustion and emission control technologies
employed. In many cases the benefits of waste reduction (the reduction of the volume of wastes via
combustion) are equal to, or more important than, the recovery of energy from the incineration process.
Major Environmental Problems Associated with Energy Activities
39
2.4.5 Electromagnetic Fields
Electric and magnetic fields (EMFs) result when electric currents pass through transmission lines
or other electrical conductors. Over the past few decades there has been increasing concern over the health
hazards of exposure to EMFs. For the siting of new power transmission lines in particular, these concerns
has become a topic of debate. The impacts of power frequency fields, those fields generated by electricity
in the 50 to 60 Hz36 range, should be distinguished from fields associated with higher frequency sources
such as radio, x-rays, or microwaves. Power frequency fields are generally confined to an area relatively
close to their source, while fields from higher frequency sources can be more broadly distributed.
While electric fields arise from a charge flowing in a conductor, magnetic fields are associated with
the motion of the charge. Electric field intensities are measured in units of volts per meter (V/m) or
kilovolts per meter (kV/m). Electric fields can be blocked by trees or building walls, and therefore
exposure to electric fields from high voltage transmission lines is primarily limited to power line right-ofways. Unlike electric fields, however, magnetic fields are not blocked by barriers such as trees or building
walls. Magnetic field strength is often presented in terms of magnetic flux density. The unit for
measurement of magnetic flux densities is the gauss (G). Flux densities from sixty-hertz power fields are
commonly reported in milligauss (mG). Both electric and magnetic fields are present in close vicinity to
electric appliances37.
The transfer of energy to cells resulting from exposure to electric and magnetic fields is relatively
minute, and therefore until the mid-1970's there was little concern over the possible negative effects of
exposure. Since then, however, epidemiological studies have suggested possible relationships between
EMF exposure and cancer risk. Increased risk associated with EMFs has been found in studies of
leukemia, male breast cancer, and central nervous system cancers for both residential and occupational
exposures (Savitz, 1993). The research suggests a roughly two-fold increase in childhood leukemia risk
with exposure to high-level residential magnetic fields.
Experimental research has not yet been able to conclusively identify a mechanism for the biological
effects of EMF exposure. EMFs do not damage DNA and therefore are unlikely to act as cancer initiators,
but EMFs may act as cancer promoters, or co-promoters. EMF exposure has been linked to changes in
melatonin hormones, calcium ions, cell division intervals, and cell growth. Further research is needed to
more carefully examine the relationships between EMF exposure and negative health impacts, especially
considering the wide-spread presence of EMF's in electrified societies. Reflecting the uncertainty over
the definition of correct dose parameters and health effects, the Environmental Data Base does not currently
contain a category for EMF exposure.
2.4.6 Occupational Health and Safety
Exposure to many environmental hazards are more intense in the work place than in the general
environment. In the United States, a review of occupational health and safety standards indicate that
society is willing to tolerate conditions and exposures in the workplace that are 10 to 100 times worse than
in the general environment (Ehrlich, Ehrlich, and Holdren, 1977). To some degree insurance and wages
36 The Hertz, abbreviated Hz, is a unit that measures the frequency with which a field (or other physical phenomenon) vibrates.
One Hz is equal to one vibration per second.
37 Much of the information on EMFs given here is drawn from OTA, 1989. This document provides a thorough background
on EMFs and their potential biological effects.
40
A Guide to Environmental Analysis For Energy Planners
are assumed to compensate workers for accepting the risks associated with their workplace. Nevertheless,
recognizing that market forces alone are unable to establish an "optimal level" of workplace hazard
exposure, occupational health and safety standards are set in many countries.
Occupational health and safety risks are of acute and chronic types. Underground coal mining
exposes workers to acute hazards such as explosions, entrapment, equipment accidents, or tunnel collapse,
and chronic exposure to conditions that can lead to health problems such as black lung disease. Data is
generally more available, and less controversial, for acute occupational hazards, such as the number
accidents that lead to death, disability or illness. In the United States accidental deaths and injuries are
much more common off-the-job than they are on-the-job, with motor vehicle accidents outweighing on-thejob accidents by a factor of more than two (U.S. Department of Commerce, Statistical Abstract of the
United States 1992, Table 666, p. 419). The industry group of mining and quarrying, which includes oil
and gas extraction, had the highest on-the-job death rate -- 43 per 100,000 workers -- of any industry group
in the United States in 1990, although the mining and quarrying rate was only slightly higher than that for
agriculture -- including forestry and fishing -- and the construction industry (ibid.: Table 665, p. 419).
When accident-related injuries and illnesses are considered in addition to deaths, mining and utilities are not
near the top of the list, ranking well below a number of manufacturing and agricultural industries (ibid.:
Table 668, p. 420).
Although quantification is a more challenging task, chronic exposure hazards are also certain to
exist. Studies of occupational exposure to energy related hazards such as radiation, toxic chemicals, and
electromagnetic fields have shown increased cancer risks38. With cancer and other diseases that may be
associated with chronic exposures, long latency periods39 and the presence of contributing or mitigating
factors complicate the search for a clear understanding of certain occupational hazards.
2.4.7 Large-Scale Accidents
A number of energy technologies are associated with the remote possibility of accidents that have
catastrophic environmental consequences. It is often difficult for the public, or energy planners, to assess
this type of hazard, even if -- although this is rarely the case -- adequate technical information is available.
One approach, probabilistic risk assessment, estimates overall risk according to both the severity and the
probability of an event. Such analysis provides an indication of comparative risk, but the public and
decision makers are likely to perceive and react to different types of risk in complex, and sometimes even
inconsistent fashions. In general individuals are willing to accept much higher levels of voluntary risk than
involuntary risk, and energy facilities primarily expose the public to the latter (Starr, Rudman, Whipple,
1976).
In the realm of low probability/high consequence accidents nuclear energy tends to receive the most
attention, but other energy technologies are also potential sources for rare catastrophic events. The
impoundment of water for hydroelectric projects can cause earthquakes (see Box 2.4). Dam failures can
result in catastrophic flooding. Liquefied natural gas (LNG) and liquefied petroleum gas (LPG) facilities
are another source of potentially catastrophic accidents, as a spill of these materials could lead to massive
explosions. Large oil spills, or the burning of oil wells (as during the Persian Gulf war) are examples of
the catastrophic environmental possibilities of accidents at oil facilities.
38 For example see Savitz (1993) referring to electromagnetic fields and electric workers. It is beyond the scope of this
document to more fully discuss findings from occupational epidemiology, but for further information the reader is urged to
consult the several references provided elsewhere in this section under individual hazard headings.
39 The periods between exposure of a person to cancer causing substances and the onset of cancer itself.
Major Environmental Problems Associated with Energy Activities
41
In the end, making decisions based upon risk assessments is more than a strictly analytical task,
there are a large number of moral and political components involved in the comparison of different types of
risk and the willingness to accept risks. Energy planners face a challenging task when incorporating these
issues in their decision-making framework.
2.4.8 Aesthetic, Visual, and Other Concerns
In many cases energy planning decisions will be influenced not only by the environmental impacts
described above, but by a less tractable set of considerations relating to how, for example, an energy
facility might “fit in” to its proposed neighborhood. Aesthetic and visual considerations, for example, can
cause a power plant to be rejected for a site that is otherwise “ideal”. Perhaps the exhaust stack from the
plant would spoil a beautiful vista, or would discourage tourists from visiting the area (thus harming the
local economy) simply by its presence. Facilities such as power lines in remote areas can detract from
wilderness recreation experiences. Even the presence of wind turbines in an area might make residents
nervous about equipment failure, even if such fears are unjustified. Wind power, in fact, while having few
of the environmental impacts of, for example, fossil-fueled power plants, does raise a host of additional
environmental considerations, as described in Box 2.5.
Other concerns that fall under this general category include cultural and anthropological impacts.
In Hawaii, for example, some groups oppose the use of geothermal power as being a desecration of the
volcano goddess, Pele. Their opposition on cultural grounds is thus in addition to concerns over the direct
environmental emissions of the proposed geothermal plants. Construction and operation of energy
facilities may also intrude on or (in extreme cases) destroy ceremonial native hunting, meeting, or burial
grounds, and in some cases could even render inaccessible important archaeological sites.
Noise generated by operating energy facilities can also be considered an environmental emission,
and plays a role in the siting of certain types of plants. The addition of an energy facility to a
neighborhood can also increase vehicle traffic; increased traffic has its own environmental consequences.
Aesthetic, visual, and other concerns are rarely directly amenable to quantitative analysis, but can
often play a key role in determining whether or not an energy project can be and ultimately is implemented
in a given area.
42
A Guide to Environmental Analysis For Energy Planners
BOX 2.5:
POTENTIAL ENVIRONMENTAL AND SOCIAL IMPACTS OF
WIND POWER DEVELOPMENT AND OPERATION
SOURCE OF IMPACT
DESCRIPTION
Land Requirements
Wind farms require a large land area, due to the requirement that the
individual turbines in a wind farm must be spaced well apart to avoid
interference. In most instances, however, activities such as farming and
ranching can go on relatively unimpeded within the wind farm site.
Noise
Noise from wind turbines comes primarily from the rotor blades as they slice
through the air. Although wind machines built recently make substantially
less noise than earlier models, noise from wind machines is potentially a
problem if wind farms are sited too close to residences.
Bird Strikes
Birds can fly into fast-moving rotor blades of wind machines and be killed.
While evidence to date indicates that birds generally learn to avoid the
spinning rotors, some problems with bird strikes have been noted.
Interference with
Telecommunications
Wind turbines interfere with television (mostly) and other
telecommunications signals, but these impacts seem to typically be localized
to the vicinity of the windfarm.
Safety
Like any industry that includes moving machinery, safety is an issue with
wind farm. Particular hazards from equipment failure include injury from
equipment failures such as blades breaking off. Safety issues have been
taken into account in wind turbine design, however, and there have been no
reported public injuries from wind energy.
Visual Impacts
The presence of wind turbines produces changes in views and skylines, and
thus have a visual impact on their the area in which they are cited. Visual
impacts may be an especially important consideration if the turbines are to
be located in pristine or wilderness areas. The access roads and power
lines needed for grid-connected turbines can cause additional aesthetic
impacts.
Source: M.J. Grubb and N.I. Meyer, Chapter 4, “Wind Energy: Resources, Systems, and Regional
Strategies” in Johansson et al, 1993.
Description of Major Environmental Effects Categories
43
3. Description of Major Environmental Effects Categories
3.1 Introduction
The long and diverse list of the potential environmental impacts of energy systems presented in
Chapter 2 demonstrates the need to consider a wide range of impacts when performing energy and
environmental analysis. Although the consideration of many different impacts is admittedly more difficult,
there is a very real danger, if one considers only a narrow range of impacts, of missing important
considerations. As a simplistic example, let’s say you wish to examine two different scenarios of electricity
generation. In the first, only coal- and oil-fired power plants are to be used. In the second, most of the new
power will be supplied by hydroelectric plants. If you restrict your analysis to, for example, air pollutant
or greenhouse gas emissions, the first scenario will appear much worse from an environmental perspective.
This approach, however, misses the sometimes substantial environmental impacts of building and operating
a hydroelectric facility, including displacement of populations and changes in river flow; inclusion of these
impacts in weighing the alternatives might lead you to make a different choice between the two scenarios.
While it is rarely possible to cover all of the impacts of an energy system in a quantitative manner, it is
important to design your analysis, and the analysis tools that you use, to enable you to take the full range of
important impacts into account.
Although the Environmental Database (EDB) provides information on a wide range of
environmental concerns, there are a number of types of environmental impacts, especially those that are
typically described in qualitative terms, that it does not yet cover. EDB lacks information, for example, on
the land requirements of energy facilities. Similarly, there are no data on the noise or aesthetic impacts of
energy systems, which are often very site-specific. In many cases it is difficult to specify a direct causal
relationship between energy activities and their associated environmental impacts; EDB focuses on impacts
where causal relationships tend to be direct. In addition, there are many instances in EDB where impact
categories exist for a particular energy-using device or facility, but no data are yet available. Even in such
instances when quantitative data on an impact are not readily available, it is important for the analyst to
keep them in mind for at least qualitative consideration, as these “non-countable” impacts may be as or
more important than the impacts that can be enumerated.
EDB includes coefficients describing the emissions and other direct impacts of the production and
use of energy. EDB is organized as a matrix, with its rows being sources of emissions and impacts, and
its columns being the different types of emissions and impacts. The matrix entries are referred to in EDB as
effects or environmental loadings. Figure 3.1 shows how information is organized in EDB.
44
A Guide to Environmental Analysis For Energy Planners
The remaining text in this Chapter
presents the loadings categories currently used
in the Core database of EDB, providing, for
each of the over 40 Effects, a brief description
of the category and the unit of measure of the
loading, and a quick review of the major
sources and environmental impacts of each
type of emission or impact.
Figure 3.1:
EDB Program Structure
Coefficients Database
Effect categories
Source
categories
SOx NOx CO CO2 . . .
Demand
devices
Transformation
processes
Environmental coefficients,
documentation and references
In EDB, Effects categories are
described with a three-tiered labeling system.
Bibliographic Reference Database
The first Effect label describes the media of the
Author
Title
Publisher Date
emission or impact (for example, "Air
Emissions"). The second label describes the
general type of emission or impact (such as
"Hydrocarbons"), and the third-level label
describes the specific species or type of emission or impact (like "Aldehydes"). Table 3.1, below, lists the
effects categories that currently appear in EDB, and the following matrix in Table 3.2 provides a quick
overview of the correlation between the effect categories and their environmental impacts. The text that
follows these summaries is organized to correspond to the order of the EDB Effects list, and discusses each
third-level effect category within the context of the broader second-level emission types, as appropriate.
Description of Major Environmental Effects Categories
45
Table 3.1:
EFFECT CATEGORIES IN THE ENVIRONMENTAL DATA BASE
AS OF EARLY 1995
AIR EMISSIONS (Level 1)
Level 2 Description
Level 3 Description
Unit Type
CARBON DIOXIDE
NON-BIOGENIC
BIOGENIC
TOTAL
TOTAL
ALDEHYDES
FORMALDEHYDE
BENZENE
TAR
ORGANIC ACIDS
METHANE
VOLATILE HYDROCARBONS
POLYCYCLIC ORGANIC MOLECULES
TOTAL
LEAD
ARSENIC
BORON
CADMIUM
CHROMIUM
MERCURY
NICKEL
ZINC
TOTAL
NITROUS OXIDE
TOTAL
SULFUR DIOXIDE
TOTAL
SIZE LESS THAN 10 MICRONS
FUGITIVE COAL DUST
CARBON-14
IODINE-131 (ELEMENTAL)
IODINE-131 (NONELEMENTAL)
NOBLE GASES
RADON
TRITIUM
TOTAL
TOTAL
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
RADIATION LOADINGS
RADIATION LOADINGS
RADIATION LOADINGS
RADIATION LOADINGS
RADIATION LOADINGS
RADIATION LOADINGS
MASS
ENERGY
CARBON MONOXIDE
HYDROCARBONS
TOXIC HYDROCARBONS
HYDROGEN SULFIDE
METALS
NITROGEN OXIDES
SULFUR OXIDES
PARTICULATES
RADIOACTIVE
AMMONIA
THERMAL EMISSIONS
46
A Guide to Environmental Analysis For Energy Planners
Table 3.1 (Continued):
EFFECT CATEGORIES IN THE ENVIRONMENTAL DATA BASE
AS OF JUNE 1993
WATER EFFLUENTS (Level 1)
Level 2 Description
Level 3 Description
Unit Type
SOLIDS
TOTAL
SUSPENDED
DISSOLVED
BIOCHEMICAL
CHEMICAL
TOTAL
TOTAL
CADMIUM
CHROMIUM
COPPER
IRON
MERCURY
ZINC
TOTAL
TOTAL
TOTAL
TOTAL
OIL AND GREASE
TOTAL
TOTAL
TOTAL
TRITIUM
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
MASS
ACTIVATION & FISSION PRODUCTS
TOTAL
RADIATION LOADINGS
ENERGY
Level 2 Description
Level 3 Description
Unit Type
MINING WASTE
TOTAL
ASH
SCRUBBER SLUDGE
RADIOACTIVE
INERT
TOTAL
TOTAL
TOTAL
LOW-LEVEL (CURIES)
LOW-LEVEL (VOLUME)
MASS
MASS
MASS
MASS
RADIATION LOADINGS
VOLUME
OXYGEN DEMAND
SULFATES
METALS
SALTS
NITRATES
PHOSPHATES
ORGANIC CARBON
CHLORIDES
AMMONIA
CYANIDE
RADIOACTIVE
LOADINGS
THERMAL EMISSIONS
RADIATION
SOLID WASTES (Level 1)
OCCUPATIONAL HEALTH AND SAFETY (Level 1)
Level 2 Description
DEATHS
INJURIES
WORK DAYS LOST
Level 3 Description
TOTAL
TOTAL
TOTAL
Unit Type
DEATH
INJURY
WORK DAY LOST
Description of Major Environmental Effects Categories
47
Table 3.2:
POTENTIAL ENVIRONMENTAL IMPACTS BY EDB EFFECTS CATEGORY
EDB "Effects" Category
AIR EMISSIONS
Carbon Dioxide/Non-Biogenic
Carbon Dioxide/Biogenic
Carbon Monoxide/Total
Hydrocarbons/Total, Volatile
Hydrocarbons/Aldehydes, Formaldehyde
Hydrocarbons/Benzene
Hydrocarbons/Tar
Hydrocarbons/Organic Acids
Hydrocarbons/Methane
Hydrogen Sulfide/Total
Metals/Lead
Metals/Arsenic, Cadmium, Chromium, Mercury
Metals/Boron, Nickel, Zinc
Nitrogen Oxides/Total
Nitrogen Oxides/Nitrous Oxide
Sulfur Oxides/Total, Sulfur Dioxide
Toxic Hydrocarbons/Polycyclic Organic
Molecules
Particulates/Total, <10 Microns, Fugitive Coal
Dust
Radioactive/(All Types)
Ammonia/Total
Thermal Emissions/Total
Climate
Change
X
N1
m
m
m
m
m
X
X
Acid
Precip.
m
m
m
X
m
m
X
m
X
m
m
m
Local
Air Polln
X
X
X
X
X
X
m
X
X
m
m
X
m
X
m
Human
Health
Effects
Materials
Economic
Impacts
X
X
X
X
X
X
X
X
m
X
X
Impacts
on
Terrestrial
Ecosyste
ms
Impacts
on
Aquatic
Ecosystems
X
X
X
X
X
X
X
X
X
X
X
X
m
X
X
X
X
m
X
X
X
X
X
X
X
X
m
X
X
X
X
X
X
X
X
X
X
X
m
m
X
m
X
X
m
m
X
m
m
X
m
Concen.
in Food
Chains
Land
Use
Impacts
Aesthetic
and Other
Impacts
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Notes:
X = Effects have possible impacts in indicated group.
m = Effects have possible impacts in indicated group, but any impacts are indirect or are likely to be minor.
N1
Carbon dioxide emitted during combustion of biomass fuels will have an effect on global warming only if the fuels are produced
in a non-sustainable manner.
"Materials and Economic Impacts" include degradation of man-made materials by emissions, and the economic costs of repairing
pollution damage, and lost economic opportunities.
"Impacts on Terrestrial Ecosystems" include impacts on both managed (e.g. agricultural) and natural ecosystems; "Impacts on Terrestrial
Ecosystems" include effects on fisheries, wetlands, and groundwater.
"Aesthetic and Other Impacts" include impacts on air and water clarity, recreational opportunities, and social and cultural impacts.
X
48
A Guide to Environmental Analysis For Energy Planners
Table 3.2 (Continued):
POTENTIAL ENVIRONMENTAL IMPACTS BY EDB EFFECTS CATEGORY
EDB "Effects" Category
WATER EFFLUENTS
Solids/Total, Suspended, Dissolved
Oxygen Demand/Biochemical, Chemical
Organic Carbon/Total
Organic Carbon/Oil and Grease
Sulfates/Total
Metals/Total, Cadmium, Chromium, Mercury
Metals/Copper, Iron, Zinc
Salts/Total
Nitrates/Total
Phosphates/Total
Chlorides/Total
Ammonia/Total
Cyanide/Total
Radioactive/(All Types)
Thermal/Total (If new EDB cat. is added)
SOLID WASTES
Mining Waste/Inert
Total
Scrubber Sludge/Total
Radioactive/Low Level (All Types)
Human
Health
Effects
m
m
X
X
m
X
m
m
m
m
m
m
X
X
X
X
Materials/
Economic
Impacts
X
m
X
X
Impacts on
Terrestrial
Ecosystems
m
X
m
m
m
m
m
m
X
X
X
m
X
m
m
m
m
m
m
m
X
X
m
X
Impacts on
Aquatic
Ecosystems
X
X
X
X
X
X
m
X
X
X
X
m
X
X
X
X
X
m
X
Concent. in
Food Chains
Land Use
Impacts
X
X
m
X
X
X
X
Aesthetic
and Other
Impacts
m
m
m
m
X
X
X
X
X
X
X
X
X
X
X
X
X
m
X
X
X
X
X
X
X
X
X
OCCUPATIONAL HEALTH AND SAFETY
Deaths/Total
X
X
X
Injuries/Total
X
X
X
Work Days Lost/Total
X
X
X
Notes:
X = Effects have possible impacts in indicated group.
m = Effects have possible impacts in indicated group, but any impacts are indirect or are likely to be minor.
"Materials and Economic Impacts" include degradation of man-made materials by emissions, and the economic costs of repairing
pollution damage, and lost economic opportunities.
"Impacts on Terrestrial Ecosystems" include impacts on both managed (e.g. agricultural) and natural ecosystems; "Impacts on Terrestrial
Ecosystems" include effects on fisheries, wetlands, and ground water.
"Aesthetic and Other Impacts" include impacts on air and water clarity, recreational opportunities, and social and cultural impacts.
3.2 Air Emissions
EDB covers several classes of air emissions, including the so called "criteria" pollutants, toxic air
pollutants, greenhouse gasses, particulate matter, and others. All coefficients for emissions to the air, with
the exception of radioactive and thermal emissions, are presented on a mass basis, for example, kg of
carbon dioxide per unit fuel consumed.
Carbon dioxide (CO2), the major greenhouse gas both in terms of quantity emitted and in its
overall effect on global warming, is released whenever a fuel that contains carbon is combusted, or
oxidized. It is released in quantities generally proportional to the carbon content of the fuel. CO2 emission
factors in EDB were principally estimated based on fuel carbon content, as described in Section 4.3 of this
manual. Carbon dioxide is not directly toxic to most plants and animals40, thus its principal environmental
40 Though humans, animals and other aerobic organisms cannot live in an atmosphere of pure carbon dioxide because they
cannot live without oxygen.
Description of Major Environmental Effects Categories
49
impact is on climate, as has been discussed in Section 2.1, in the previous chapter. CO2 emissions from
fossil and biomass fuels are treated separately in EDB as "Non-Biogenic" and "Biogenic" carbon dioxide,
respectively. As carbon dioxide is taken up and emitted by many terrestrial and oceanic sources and sinks,
its lifetime in the atmosphere is difficult to specify, but may be on the order of 100 years41. CO2 emission
factors are provided in EDB for most for most source activities involving fuel combustion, and most of the
CO2 factors in EDB are derived based on fuel carbon content.
Non-biogenic ("fossil fuel") CO2 : Non-biogenic emissions are those derived from combustion
of fossil fuels and other sources of carbon dioxide (such as geothermal wells) for which the carbon
emitted is either of geological origin or, as is the case with coal, oil, gas, and peat, was formed
from biological material but on geological time scales, that is, so long ago that the fuels are
essentially non-renewable. Non-biogenic emissions constitute a net addition of CO2 to the
atmospheric pool of the gas, at least on a human time scale.
Net Biogenic CO2.. Biogenic emissions of carbon dioxide, in contrast, result from biomass
combustion, and do not constitute net additions of CO2 to the atmosphere, under conditions of
sustainable biomass harvesting. Under these conditions, the CO2 released upon combustion of
biomass-derived fuels can be recaptured during photosynthesis in the next biomass growth cycle42.
Non-sustainable harvesting of biomass, leading to soil and land degradation and, in extreme cases,
to deforestation and desertification, will cause net additions of CO2.
Carbon monoxide (CO) is produced, in concentrations that vary widely across different types of
combustion devices, when carbon-based fuels (both fossil and biomass fuels) are burned. CO results when
combustion of these fuels is incomplete, that is, when the carbon in a fuel is not completely oxidized to
carbon dioxide. As a consequence, emissions of carbon monoxide are primarily a function of combustion
conditions; inefficient combustion generally increases CO emissions. Motor vehicles tend to be the major
source of CO emissions in most areas, with older vehicles being the primary culprits. Carbon monoxide is
created in oxygen-starved, fuel-rich combustion conditions, such as by low speed and idling vehicles in
congested urban areas. Household biomass- and coal-burning stoves are also significant sources of CO,
while industrial boilers and utility power plants, for example, will produce relatively little CO when
operated properly. Carbon monoxide is converted (oxidized) in the atmosphere to CO2, and typically
remains in the atmosphere for a few months at most43. Emission factors for carbon monoxide are provided
for many emissions sources in EDB, and are derived from many sources, especially USEPA documents44.
Carbon monoxide is a local air pollutant, with respiratory impacts, and contributes both directly
(as it oxidizes to CO2) and indirectly to the increase in greenhouse gas concentrations in the atmosphere.
CO's respiratory impacts on human and animal health stem primarily from the ability of the CO molecule
to bind to hemoglobin, the oxygen-carrying molecule in blood, and thereby reduce the supply of oxygen to
the brain in human and other tissues. Since carbon monoxide binds more readily to hemoglobin than
oxygen, even relatively low concentrations of CO in the air can lead to carbon monoxide poisoning, which
41U.S. Environmental Protection Agency, Policy Options for Stabilizing Global Climate, Report to Congress, Main Report,
December 1990. USEPA Division of Policy, Planning, and Evaluation, Washington, D.C., USA. Report No. 21P-2003.1, page
II-38.
42 For example, if a hectare of corn were grown to produce 3,000 liters of ethanol, and the ethanol was then used as fuel, there
would be a temporary addition of CO2 to the atmosphere, but the next year, planting the same hectare of corn would reclaim a
similar quantity of carbon dioxide from the atmospheric pool. The key here is that biogenic emissions of CO2 can result in no
net addition of CO2 to the atmosphere, and no net loss of carbon from the terrestrial biomass.
43USEPA 1990c, ibid.
44Please see the attached Annotated Bibliography of EDB References for further information about EDB data sources.
50
A Guide to Environmental Analysis For Energy Planners
is characterized by headaches, dizziness, and nausea in mild cases, and loss of consciousness and death in
acute cases45.
Hydrocarbons (sometimes abbreviated as HC, or VOC--for volatile organic carbon), are emitted
from energy-sector activities as either 1) products of incomplete combustion of carbon-based fuels, or 2) by
evaporation or leakage of fuels and lubricants from fuel production, transport, and storage facilities (for
example, oil wells, tanker ships and trucks, and petroleum refineries) or from fuel-using devices (such as
automobile gas tanks and engine crankcases). Individual hydrocarbon species exhibit various degrees of
toxicity in different animal species. Many hydrocarbons are also carcinogenic (promote the growth of
cancers) and/or promote genetic mutations that can lead to birth defects. Hydrocarbons can also be
bioconcentrated as discussed in Section 2.2, leading to amplified toxic effects in animals at the top of the
food chain. As a class, hydrocarbons contribute to the production of photochemical smog and of ground
level ozone, which are dangerous to human health due to effects on the respiratory system . High ozone
levels also damage crops, forests, and wildlife, as described in Box 3.1, below.
With the exception of methane, hydrocarbons as a class are likely to contribute indirectly to global
warming through their effect on tropospheric ozone concentrations (methane contributes directly).
Different hydrocarbon species have different lifetimes in the atmosphere, with some chemicals having
lifetimes of hours or days, while other, less reactive molecules remain in the atmosphere longer. As of
April 1995, total hydrocarbon emission factors are reported for many EDB Source categories, as are
methane emissions, but there are relatively few emission factors for the other hydrocarbon species and
classes. Most of the hydrocarbon and methane emission factors in EDB are derived from USEPA
literature, while emission factors for other types of hydrocarbons are often from U.S. Department of
Energy documents.
BOX 3.1:
SOURCES AND IMPACTS OF TROPOSPHERIC (GROUND-LEVEL) OZONE (O3)
Tropospheric ozone can present a significant health risk in or downwind from many urban areas. Ozone
is a secondary pollutant, produced in the presence of sunlight, nitrogen oxides (NOx), and volatile
hydrocarbons. In the U.S., national ambient air quality standards are frequently exceeded in many
areas, particularly during the summer months. Elevated ozone concentrations can lead to acute
respiratory symptoms and aggravation of previous illnesses, and are suspected of increasing
vulnerability to chronic respiratory illness. Ozone can also cause cracking and oxidation of rubber and
other elastomers, fiber damage, and may result in damage to paint, plastics, asphalt, and other
materials.
Long-range transport of ozone and ozone precursors can lead to elevated ozone concentrations in rural
areas, where exposed crops and forests can suffer damage. Ozone damage to crops has been heavily
studied, and dose-response curves have been developed for major crops of economic value. Crop
yields can drop 15% or more under ozone stress (RCG/Hagler, Bailly, 1993).
While estimating the emissions of ozone precursors, including volatile hydrocarbons and nitrogen oxides,
can be relatively straightforward, the processes of ozone formation and destruction is very complicated;
sophisticated computer programs must be used to model atmospheric ozone chemistry.
45See, for example, Doull et al, 1980, pages 317 - 319. This reference notes that if CO has an ambient concentration of 0.1
percent by volume in air, hemoglobin in human blood will, at equilibrium, be approximately half saturated with CO and half
with oxygen. This level of CO saturation is often associated with acute carbon monoxide poisoning.
Description of Major Environmental Effects Categories
51
In addition to a category of "Total" hydrocarbons, EDB includes separate Effects categories for a
number of different hydrocarbon species, as well as for the general class of VOCs. These species, and
their general environmental characteristics, are discussed below. In addition to VOCs, subclasses of
hydrocarbon emissions often found in the literature include:
•
•
•
Non-Methane Hydrocarbons (NMHCs), a grouping often used in the greenhouse-gas field,
Total Organic Gases (TOG), and
Reactive Organic Gases (ROG)46.
These different divisions of hydrocarbon emissions can create some confusion, as they overlap
substantially, but not necessarily in a well-defined way. As a consequence it is advisable, when using
EDB, to review the coefficient entries for the total hydrocarbons "effects" category for those sources that
are of interest for information on what hydrocarbon species are included in the value given. The specific
hydrocarbon species for which effects categories are currently provided in EDB, and some of the specific
environmental hazards of those species, are described below.
Methane (CH4) is emitted as a by-product of fuel combustion, through leakage from natural gas,
oil and coal extraction, transmission, and distribution facilities, and from other agricultural and
natural (non-man-made) sources. In general, fuel combustion is a relatively minor contributor to
overall CH4 emissions relative to the other sources of the gas. Methane is relatively non-toxic to
humans and animals, but in high enough concentrations it can cause suffocation (for example,
through major methane leaks in a closed building, or methane seepage into a coal mine). Methane
is, however (as was noted in Section 2.1) a powerful greenhouse gas, contributing to global
warming both directly and (to a lesser and still uncertain extent) through its interactions with both
tropospheric ozone and stratospheric water vapor.
Aldehydes, chemically speaking, are hydrocarbons that contain an oxygen molecule attached by a
double bond to a carbon atom, which is also attached to a hydrogen atom. They have the general
chemical formula RCHO47, where R is a hydrocarbon group (such as the methyl group, -CH3).
Aldehydes are products of incomplete combustion, with motor vehicles being a major source of
emissions, and also form in the atmosphere in reactions between hydrocarbons and nitrogen
compounds, and other pollutants. Aldehydes are extremely reactive molecules, and are major
contributors to the odor and irritation of the eyes, nasal passages, and respiratory tract caused by
exposure of humans and animals photochemical smog. As reactive molecules, aldehydes may also
damage the surfaces of plants. The two main aldehyde species of concern are formaldehyde
(discussed below) and acrolein. Both are detectable by odor in the at a concentration of about 1
part-per-million, and both cause irritation of mucus membranes and other effects at concentrations
of a few ppm or less (Doull et al, 1980)48.
Formaldehyde has the chemical formula H2C=O, where "=" represents a double bond. It is
produced by incomplete combustion of hydrocarbon fuels, especially by motor vehicles. In
particular, it is one of the major hydrocarbon pollutants produced by motor vehicles operating on
natural gas, methanol, and ethanol fuels. Formaldehyde is also used as a preserving medium for
human and animal tissue samples (including as an embalming fluid), and thus has a familiar and
46The designations TOG and ROG are often used by the California Air Resources Board (CARB) in their documents, including
Methods for Assessing Area Source Emissions in California, September, 1991, CARB, Sacramento, CA, USA (CARB 1991a).
47Morrison and Boyd (1973), page 617.
48 Pages 625 - 626.
52
A Guide to Environmental Analysis For Energy Planners
readily detectable odor. Formaldehyde makes up an estimated 50 percent of the total aldehydes in
polluted air. Its effects on human and animal health are as noted under "Aldehydes", above.
Benzene is a hydrocarbon species containing six carbon atoms arranged in a hexagonal ring
structure, with a hydrogen atom attached to each carbon (C6H6). Its ring structure and the
arrangement and nature of the bonds between its carbon atoms make benzene an aromatic
compound in chemical terminology, and confer on it special reactive and toxicological properties.
Benzene is a constituent of crude oil and of refined fuels, particularly motor fuels, and is also used
as a solvent and a chemical feedstock. It is emitted, typically in concentrations ranging from a
fraction of a percent to a few percent of total hydrocarbons, by fuel combustion activities, from
refinery processes, and from oil and gas extraction, transport and storage operations (CARB
1991b). Emissions from motor vehicles are a major source of benzene.
Benzene has a number of different impacts on human health. Human exposure to benzene
in high concentrations (greater than 20,000 ppm) leads to death within minutes due to respiratory
failure and collapse of the circulatory system, but the primary cause of these responses to acute
benzene poisoning seems to be its effect on the central nervous system. In lower concentrations,
benzene affects a variety of different tissues and organs in a variety of different ways, earning the it
a description by Doull, et al (1980)49, as "an insidious and unpredictable toxicant". The effects of
benzene on health include possible effects on the central nervous system, injury to the bloodforming tissues (such as the liver) and other blood abnormalities (including anemia). Because
benzene is readily soluble in blood and in fatty tissues, it may persist in the body for several days
after exposure. One of the major concerns about chronic exposure to benzene vapor is its possible
role in promoting cancers, including leukemia. This role has been suggested by various studies.
Benzene has also been shown in animal studies to cause birth defects. Dissolved in fresh or salt
water, benzene, like other hydrocarbons, may be toxic to aquatic and marine life.
Tar is a complex and varying mixture of different hydrocarbon species, principally composed of
heavier hydrocarbon species (that is, hydrocarbon molecules with higher molecular weights).
Emissions of tar typically come from combustion of coal and of heavier petroleum fuels, such as
bunker or residual oil, and production of coke and other non-energy products. Poor combustion
conditions may increase releases of tar. The heavy hydrocarbon species in tar tend to condense
out of the air onto surfaces, including forming aggregates with particulate matter in the air.
Chronic exposure of humans and other animals to tar in the air can cause or exacerbate
respiratory problems, as tar can build up in the lungs. Tar condensing from the air can build up
on plant surfaces and interfere with plant growth. Some of the individual substances in tar may
themselves be toxic and or carcinogenic (cancer-promoting).
Organic Acids, as the name implies, are organic molecules that include acidic, or carboxyl groups
of the form -COOH. They are also referred to as carboxylic acids. These hydrocarbon species
are very reactive, and thus may not appear very often in emissions estimates because they react
with other chemical species in exhaust gasses to form new molecules before they can be measured.
Like the mineral acids (including the nitric and sulfuric acids that are produced by reaction with
sulfur and nitrogen oxides with water, as described below), organic acids have a destructive effect
on human and animal tissues, particularly as eye and respiratory system irritants. They also, due
49 Pages 485 - 488.
Description of Major Environmental Effects Categories
53
to their acidic nature, can degrade plant surfaces, thus affecting plant health, and can eat away at
natural and man-made materials and structures causing economic and ecological damage.
Volatile Hydrocarbons are a sub-class of total hydrocarbons loosely defined as those species that
do not readily condense out of the air. These species include many of the other types of
hydrocarbons listed here, and constitute the bulk of hydrocarbon emissions. The sources and
effects of this class of emissions are substantially the same as those listed above for hydrocarbons
in general. A separate category for these is emissions is provided in EDB because volatile
hydrocarbons are sometimes reported separately from (or instead of) total hydrocarbon emissions.
A separate classification for atmospheric emissions of Toxic Hydrocarbons is provided in EDB
because some key sources of emission coefficients track these species separately from general
hydrocarbon emissions. At present EDB has very few emission factors for these substances, but
estimates for emission factors exist and are being developed by a number of sources, including the
U.S. EPA and the State of California Air Resources Board. As the name implies, toxic
hydrocarbons are notable for their poisonous effect in low doses on plants and animals. One
source category for toxic hydrocarbons is provided in EDB, namely Polycyclic Organic Molecules
or POM. POM are a class of molecules containing two or more hydrocarbon "rings". In some
cases, these ring structures mimic or interact with molecules in living cells, contributing to their
toxicity. Energy sector activities that release POM and other toxic hydrocarbons include
combustion of coal and oil products, wood and wood-product wastes, municipal solid waste, and
similar fuels. Other sources of air emissions of molecules in this class include the chemical
industry, food preparation (including the frying of meats), and disposal of wastes--particularly
plastics and chemical wastes--via incineration. The major health concern for toxic hydrocarbons
are their possible or probable (depending on the species considered) effects as carcinogens or
teratogens (substances capable of causing genetic or reproductive abnormalities) in humans.
These compounds can also be bioconcentrated, and thus their emissions may have a
disproportionate effect on animals at the top of the food chain (including humans).
Emissions of Metals to the atmosphere are principally the result of combustion of fuels that
contain various metal species as trace constituents, contaminants, or additives. More rarely, atmospheric
emissions of metals may come from metal atoms that have "worn" off of combustion equipment such as
engine parts, turbine blades, or boiler grates. Many different species of metals are emitted from energysector activities, as well as from non-energy industrial activities, and their environmental effects vary with
the species and with their concentration in the air. Some metals are necessary nutrients for plants and
animals at low concentrations, but are toxic at higher levels. EDB provides a number of different source
categories for atmospheric metals emissions, but at present (1995) emission factors have been entered for a
significant number of sources only for lead emissions (based primarily on USEPA data). As most metals
are emitted as part of particulate matter, the lifetime of metals in the atmosphere is equal to that of the
particles to which they are attached, which depends on the particle size (smaller particles remain in the
atmosphere longer) and prevailing meteorological conditions.
Lead (which has the chemical abbreviation Pb) is a soft gray metal used in many applications. It
is a pollutant of major concern, due both to the amount of lead emitted and to its effects on human
health. Lead is found in widely varying concentrations in solid and unrefined liquid fuels such as
coal and crude oil--as well as in the heavier refined oil products such as residual oil--and is emitted,
often associated with particulate matter, when theses fuels are burned. By far the most important
source of lead emissions from the energy sector, however, is the lead that is used as an "anti-
54
A Guide to Environmental Analysis For Energy Planners
knock" additive in gasoline. Lead is added to gasoline as tetraethyl lead (Pb(CH2CH3)4)--a form
of lead in which short hydrocarbon chains (ethyl groups) are bonded to a lead atom--in many
countries, though its use as a fuel additive is being phased out in the United States and other
nations. In the early 1970's, the average gallon of "regular" gasoline in the United States
contained 2.6 grams of lead (0.68 g/liter; Ehrlich et al, 1977)50. This has been reduced
substantially since. More recent figures on the lead content of gasoline (grams per liter) in major
cities around the world range from 0 in Moscow to 0.026 in New York and Los Angeles, 0.15 in
Tokyo, 0.6 in Beijing, 1.16 in Manila, and 1.5 in Karachi (WHO/UNEP, 1994)51. Tetraethyl lead
emissions are cause of special concern because this form of lead is more mobile in the environment
than elemental lead (Pb metal).
Once emitted, lead may remain and be transported in the atmosphere in association with
fine particulate matter, or may settle fairly near where it was emitted (such as a roadway).
Virtually all of it eventually either settles to the ground or mixes with water in the atmosphere and
is incorporated into rain or snow. Lead can thus reach humans and other animals by being
absorbed through the skin, by being absorbed through the lungs during breathing, or by being
ingested with food or drink. Since lead can be concentrated in the food chain, its environmental
concentration may be amplified before it reaches humans and other carnivores. The symptoms of
lead poisoning on humans are well known, and include "loss of appetite, weakness, awkwardness,
apathy, and miscarriage" (Ehrlich et al, 1977)52. Lead affects many organs and systems within
the body, including the central and peripheral nervous systems, the kidneys, and the blood synthesis
and circulation systems (Doull et al, 1980)53. Domesticated and wild animals living in areas
where lead emissions are substantial are subject to lead poisoning. It has been shown that lead
levels in relatively remote areas, such as high forests in the northeast United States, have been
increasing substantially, but it is not yet known what direct effects this contamination may have on
plant growth (Freedman, 1989)54.
Arsenic metal (As) is a poison of some renown, and as a consequence finds use in insecticides and
herbicides, anti-fouling paints, and wood preservatives, as well as in forming alloys with other
metals (including lead). It is emitted to the atmosphere in relatively low concentrations from
facilities that burn coals that contain the metal as a trace contaminant. Metal smelters are another
major source of atmospheric arsenic emissions.
Arsenic compounds are more prevalent in nature than the metal itself. The symptoms of
acute arsenic poisoning (exposure to high doses of the metal over a short period--minutes or
hours) in man and animals include gastric tract disturbances, dryness of the mouth and nose,
muscle spasms, delirium, and loss of consciousness. Symptoms of chronic (exposure to lower
concentrations over a longer term) arsenic poisoning include fatigue, peripheral nervous system
problems; and blood problems. Arsenic has also been implicated as a carcinogen (that is, in
promoting the growth of cancers) and in causing birth defects. The environmental effects of
arsenic are enhanced by its tendency to accumulate in plant and animal tissues.
50 Pages 568 - 571.
51 WHO and UNEP note that these values may be average lead content figures or upper limit values.
52 Page 568.
53 Pages 415 - 421.
54 Pages 76 - 80.
Description of Major Environmental Effects Categories
55
Boron (B) is a light element that is grouped with the metals. It is a plant nutrient, and is found in
many different forms and compounds, including the detergent additive borax (Na2B4O7) and boric
acid, which is used in foods and disinfectants. Boron compounds are emitted in very small
quantities when fuels -- mostly coals -- that contain the element are burned. The acute effects of
boron compounds on the health of humans and other animals include damage to the central nervous
and respiratory systems, as well as to the kidneys, though most incidents of health problems related
to boron compounds are associated with industrial exposure, rather than to emissions from the
energy sector.
Cadmium (Cd) often occurs in nature in association with zinc and lead, and is widely used in
electroplating, in manufacturing of batteries, and in many other applications. As with arsenic and
boron, some cadmium is emitted to the air during the combustion of fuels containing the metal55,
but most of the health risks of cadmium poisoning are due to industrial emissions (for example,
emissions from metal smelters). Cadmium is toxic at very low concentrations--less than 1 ppm.
The primary health impacts of both acute and chronic cadmium poisoning are on the kidneys, the
respiratory system, and on bone formation. It has been suggested that chronic cadmium exposure
is implicated in increasing levels of hypertension (high blood pressure) in the general population,
but the link is by no means certain (Doull et al, 1980)56. Cadmium is a pollutant of some concern
for both animals and humans because it is retained in the kidneys, and, as it is not readily excreted,
tends to build up in the body and in ecosystems. Atmospheric cadmium associated with
particulate matter can be find its way into the food chain when it is deposited on plants, which are
then eaten by animals.
Chromium (Cr) is widely used for chrome plating of other metals (such as automobile steel) as
well as in paint and pigment manufacturing, in metal alloys, and in the tanning of animal skins.
Atmospheric emissions of chromium from the energy sector are from combustion of fuels
containing the element and from the wear of metal parts in combustion equipment. Chromium,
and compounds of chromium including chromate and chromic acid, can cause medical problems of
the skin, nose and throat, and liver, and may also be carcinogenic, though chromium is an essential
nutrient at low concentrations (Doull et al, 1980)57.
Apart from lead, Mercury (Hg) is perhaps the best-studied metallic pollutant. Mercury is used in
the production of chlorine (which is used in plastics manufacture) and of caustic soda, and is also
used in paints, pesticides and herbicides, medicines, wood-pulp making, metals refining, and other
applications. Like lead, mercury is a trace contaminant of oil and especially coal, though its
concentrations in these fuels vary widely (Ehrlich et al, 1977)58. It is emitted to the atmosphere
from power plants and other combustion facilities in combination with particulate matter.
Mercury occurs in the environment primarily as metallic mercury, as sulfides, sulfates, or
chlorides, or in complex with several types of organic molecules (known collectively as "organic
mercury").
55P.R. Ehrlich et al, (1977, p. 575) suggest that cadmium is present in crude oil and coal at roughly 0.5 and 1 part per million,
respectively. These authors also note that cigarette smoking is a substantial source of cadmium exposure.
56 Pages 428 - 435.
57 Pages 441 - 442.
58 Page 571 of this reference gives a range of 0.01 to 33 ppm by weight for the mercury content of different coal species.
56
A Guide to Environmental Analysis For Energy Planners
The symptoms of mercury poisoning in humans include “headache, fatigue, irritability,
tremors, and other nervous disorders"59. These neurological symptoms are the origin of the phrase
"mad as a hatter", as hat makers routinely used mercury in their trade. Mercury is retained in the
bodies of animals, and is concentrated by the food chain. The most well-publicized type of this
bioconcentration leads to high concentrations of mercury and mercury compounds in large food
and sports fish such as tuna and swordfish60. Large predatory birds have also been adversely
affected by the mercury in their food.
Nickel (Ni) is used extensively in electronics, metallurgy, batteries, and other applications, as well
as its familiar usage in coins. Nickel occurs in nature in combination with iron and copper, and is
present as a trace element in some coals and in crude and residual oils. Nickel has also been used
as a gasoline additive. Metal smelters are a significant source of atmospheric nickel. With the
exception of the compound nickel carbonyl (Ni[CO]4), nickel is not as highly toxic as mercury and
some other metals, but can, in high enough concentrations, cause nasal and lung cancers, and other
respiratory problems61. Nickel can be concentrated by certain types of plants, and nickel in the
soil (naturally-occurring or present as a pollutant) can be rendered more mobile by the action of
acidifying substances such as nitrates and sulfates (see discussion of nitrogen and sulfur oxides,
below).
Zinc (Zn) is used in large quantities for making galvanized iron and steel, in paint, and in rubber(vulcanized tires), glass-, and paper-making. Major emissions of zinc to the atmosphere are from
metal smelting activities, with coal and oil combustion making a smaller contribution. Particles
containing zinc are also released near roadways through wear of automobile parts and tires. Zinc
is an essential trace nutrient, but can be toxic in high doses, causing gastric (digestive system)
difficulties if taken in with food or drink, and "metal fume fever" when zinc oxide fumes are
inhaled, as sometimes occurs in industrial settings (Doull et al, 1980)62. Like other metals, zinc is
concentrated by aquatic and terrestrial plants, and is rendered more mobile in the environment by
acidification of soils or waters (for example, due to acid deposition; Freedman, 1989)63.
Nitrogen Oxides (NOx), comprise a group of molecules that can contribute to local air pollution,
acid deposition, and global climate change. They are among the most frequently reported atmospheric
emissions, and the most commonly regulated. Nitric oxide (NO) is generally produced during hightemperature combustion. It is photochemically oxidized to nitrogen dioxide (NO2) in the atmosphere.
Nitrous oxide (N2O), a potent greenhouse gas, is produced at much lower levels, and is discussed below.
The nitrogen in nitrogen oxide combustion products is derived from nitrogen present in various
compounds in the fuel and from molecular nitrogen (N2) that makes up nearly four-fifths of molecules in
the air. Higher combustion temperatures (which generally promote more complete combustion) tend to
increase NOx formation, as more N2 from the air is oxidized. It is important to stress that the role of
atmospheric nitrogen in NOx formation means that combustion of even "clean" fuels such as natural gas,
methanol, or hydrogen, which contain at most trace amounts of nitrogen, can produce substantial amounts
of nitrogen oxides. The presence or absence of metals and other surfaces that can catalyze (increase the
59P.R. Ehrlich et al, (ibid, p. 572), Doull et al (eds), 1980, ibid. Pages 421 - 428.
60Mercury concentrations five to ten thousand times higher than the average concentration in seawater have been found in large
fish. .
61Doull et al, 1980, pages 265, 452; Freedman, 1989.
62 Pages 461-462.
63 Pages 78, 105.
Description of Major Environmental Effects Categories
57
rate of) formation or destruction of NOx also plays a role in determining the overall level of nitrogen oxide
emissions.
As shown in Table 2.4 above, natural and anthropogenic sources account for approximately equal
shares of global emissions. However, since about three-quarters of human NOx emissions result from fossil
fuel combustion, much of this from vehicles, urban areas can experience elevated NOx concentrations.
Once emitted, NO and NO2 have atmospheric lifetimes on the order of months64.
Nitrogen oxides can contribute to environmental problem in several ways. Short-term exposure to
elevated NO2 concentrations (0.2 to 0.5 ppm) can cause respiratory symptoms among asthmatics. Indoor
fuel combustion, particularly from gas stoves or traditional fuel use, can lead to elevated indoor levels
which have been associated with increased respiratory illness and reduced disease resistance among
children. (RCG/Hagler, Bailly, Inc., 1993). Nitrogen oxides contribute to the formation of tropospheric
ozone and nitrate aerosols (fine particulates), major air pollutants that are discussed in Box 3.1. NOx
species also may have a role in global warming (see Section 2.1), but the extent of this role is still a subject
of debate.
Atmospheric emissions of NOx contribute to the formation of the photochemical smog prevalent in
many urban areas, and thus have a general detrimental effect on the respiratory health of humans and other
animals, as well as on visibility. In high concentrations, NOx can injure plants, though the required
concentrations usually only exist near a large point source of the pollutant. The major hazard to plants
from nitrogen oxide emissions may be through the effect of NOx on ozone formation (Freedman, 1989)65.
Atmospheric nitrogen oxides in high concentrations cause respiratory system damage in animals and
humans, and even in relatively low concentrations they can cause breathing difficulties and increase the
likelihood of respiratory infections, especially in asthmatics and other individuals with pre-existing
respiratory problems (Doull et al, 1980)66.
EDB provides two categories for nitrogen oxides: a Total effect category, and a separate category
for nitrous oxide, which as a greenhouse gas has properties distinct from the rest of the group.
Emission factors for total nitrogen oxides are provided for many of the fuel-combustion source
categories in EDB, and most have been taken or derived from U.S. EPA documents. Emission
factors for nitrous oxide are available for a smaller subset of EDB sources, and are at this time
quite uncertain. Most of the N2O factors in EDB are also derived from U.S. EPA documents.
Nitrous oxide (N2O) is a very powerful greenhouse gas (on a weight basis) but, as indicated
above, although the quantities emitted are subject to large uncertainty, they appear to be a small
(but highly variable) fraction of total nitrogen oxide emissions. The process of N2O formation
during and after combustion is still poorly understood. Unlike the other nitrogen oxides, nitrous
oxide has a lifetime in the atmosphere of approximately 150 years (USEPA, 1990c). A recent
systematic error in the measurement of nitrous oxide emissions has left the actual magnitude of
N2O emission factors in some doubt, as is discussed in section 4.4.
Hydrogen Sulfide (H2S) has a distinctive odor most often associated with rotten eggs, and the
human nose can detect it in very low concentrations (about one part per billion in air). It is emitted during
64Note that once emitted, NO is often oxidized to nitrogen dioxide by combination with oxygen in the air.
65 Pages 16-17.
66 Pages 622-625.
58
A Guide to Environmental Analysis For Energy Planners
extraction of oil, natural gas, and geothermal energy, from some industrial processes, from municipal
sewage and waste disposal, and from a number of natural sources, including volcanic areas and wetlands.
It is thus a pollutant of major importance mostly in the locales of major energy and industrial facilities.
Hydrogen sulfide in relatively high concentrations is toxic to humans and animals. In non-lethal
concentrations it is an irritant of the eye and of the respiratory system (Doull et al, 1980)67. In the
atmosphere, hydrogen sulfide is oxidized to sulfur oxides (SO2 , SO3, and sulfates, which have
environmental effects of their own, as noted below) with an average lifetime (as H2S) of less than a day
(Freedman, 1989). Hydrogen sulfide emission factors are provided in EDB primarily for geothermal
electricity generation facilities, and were derived from U.S. Department of Energy documents.
As with nitrogen oxides, two source categories are provided for Sulfur Oxides (SOx) in EDB.
The first, Total sulfur oxide emissions (including sulfur dioxide SO2, sulfur trioxide SO3, and sulfate SO42-)
covers all of the different species of sulfur oxide emissions, while the second, Sulfur Dioxide, covers only
SO2, the major SOx species released to the air by human activities. Quite often, in the emission factor
literature, total SOx emissions will be expressed as SO2 equivalents. Total SOx emission factors are
provided for many EDB source categories, and most of these emission factors are drawn from U.S. EPA
documents. EDB reports SO2 emissions separately from SOx emissions more rarely, typically when the
document from which an emission factor is drawn specifies that the emissions reported are of sulfur
dioxide.
Energy related sulfur oxide emissions are generally proportional to the fraction of sulfur in fuels
such as coal and crude oil. For some fuels, the fraction of sulfur can exceed 10 percent. The fuels with
the most sulfur are the coals and heavy oils used in electric-utility and heavy industrial boilers. When these
fuels burn, sulfur combines with oxygen in the combustion air to yield SOx. Metal smelters and other
industrial processes are also key sources of SOx emissions.
Sulfur oxides can react with water and oxygen in the atmosphere to yield sulfuric acid, one of the
major components of acid rain. (The impacts of acid deposition were discussed in Section 2.2). SO2 itself
can damage plants, with acute exposure to the gas causing death of part or all of a plant, and chronic
exposure, though the threshold at which plants are affected varies widely among different plant species
(Freedman, 1989)68. In humans, exposure to SO2 at high levels (above about 5 ppm; the average
concentration in urban air in the U.S. is about 0.2 ppm) causes respiratory problems (Doull et al, 1980)69,
though exposure of to significantly lower doses can sometimes exacerbate existing respiratory problems in
sensitive individuals. In developing countries and other areas where coal is used as a home heating and/or
cooking fuel, SOx can be an important health hazard as an indoor air pollutant.
Particulate emissions, sometimes abbreviated TSP for Total Suspended Particulates, are, as one
would guess from the name, microscopic particles of soot and ash -- which often include other substances
such as metals, hydrocarbons, and sulfur compounds-- that are emitted from combustion processes or are
carried into the air from roads, agricultural activities, or during transport or storage of finely divided solid
materials such as crushed coal.
Anyone who has traveled down a dusty road can appreciate the effect of particulate emissions on
the human upper respiratory system (nose, throat), but smaller particles can also penetrate deep into the
lungs, where they can aggravate existing respiratory problems and increase the susceptibility to colds and
67 Pages 328 - 330.
68 Pages 10-16.
69 Pages 611-619.
Description of Major Environmental Effects Categories
59
other diseases. Particulates can also serve as carriers for other substances, including carcinogens and
toxic metals, and in so doing can increase the length of time these substances remain in the body.
Particulate matter in the air impairs visibility and views, and particulate matter settling on buildings,
clothes, and other humans may increase cleaning costs or damage materials. Particulate matter is an
important indoor air pollutant in areas where open or poorly-vented household cooking and heating
equipment is used, particularly with "smoky" fuels such as wet biomass, crop and animal residues, and
low-grade coals. Particulate matter can settle on plants, reducing plant growth by reducing plants' uptake
of light and carbon dioxide.
The amount of particulate matter emitted during combustion is a function of the fuel type, the
amount of non-combustible fuel contaminants such as ash present in the fuel, the firing conditions, and the
level of pollution control equipment used. TSP emissions cover a wide range of particle sizes, from those
that are nearly visible to the naked eye to particles less that a micron (one millionth of a meter) in diameter.
The size classifications of particulate matter are important, as A) the smaller the particle, in general, the
longer it will remain in the atmosphere, and the farther it can be dispersed from its source, and B) particles
in smaller size ranges are a more serious concern to human health, as, unlike larger particles, they are not
filtered out by the upper respiratory system.
EDB provides three source categories for particulate emissions. Entries in the Total particulate
category give the mass of all particles emitted per unit fuel consumed or produced. These entries
are provided for many source categories in EDB, and, as with most of the criteria pollutants, are
derived primarily from U.S. EPA documents and databases, with data on biomass fuel combustion
coming from a variety of international sources.
The second category of particulate emissions counts those particles of Size Less Than 10 Microns
in diameter, often abbreviated "PM10" in the literature. This is the most commonly cited size
class, and includes those emissions of most concern to human health. PM10 emissions are given
for a large number of EDB categories, though many categories only have data for total emissions.
The U.S. EPA, the California Air Resource Board, and others maintain "speciation" manuals and
databases of the size classes of particulate emissions by emission source. These can be used, if
appropriate, to expand the data in EDB to additional size categories.
A separate source category under particulates is provided for Fugitive Coal Dust, that is, coal
dust that escapes from coal trains and other transport system, or is emitted during the production,
processing and storage of coal. EDB contains relatively few entries for this specific particulate
pollutant; most derived from U.S. Department of Energy documents. Coal dust is of special
concern as a particulate pollutant due to the presence in the coal particles of heavy metals and
other trace coal constituents. It is inhalation of coal dust that causes the "black lung" disease
frequently seen among coal miners, particularly in mining operations where mine ventilation and
dust masks are inadequate.
Radioactive emissions to the atmosphere stem primarily from the operation, maintenance, and
decommissioning70 of nuclear power plants and the production, refining, storage, and disposal of the
materials that fuel them, but can also be released in very small quantities during activities such as coal
mining and combustion. Non-energy sector activities that emit radioactivity include medical X-rays and
70Decommissioning refers to the process of dismantling a nuclear power plant when its lifetime is complete, and rendering it
and the nuclear materials it used and generated stable and "safe" for long-term storage.
60
A Guide to Environmental Analysis For Energy Planners
other health science applications of radiation. Emissions during operation of nuclear power plants can be
direct emissions (either routine or accidental) from the reactor itself, emissions of "activation products"
(such as metals that are part of the reactor that have been irradiated by operation of the reactor and have
become radioactive themselves), and emissions from low-level and high-level wastes in storage. Emissions
of radioactive materials are typically measured in Curies, abbreviated Ci, which specifies the number of
particles emitted per second from a radioactive material.
The effects of radioactive emissions on human health have been documented by the population
exposed following the explosion of the nuclear bombs over Hiroshima and Nagasaki in Japan, and by the
Chernobyl reactor accident in the Ukraine. These health effects include acute effects such as radiation
sickness (characterized by nausea, damage to bone marrow, and other symptoms), and chronic effects such
as increases in cancer rates, genetic effects, prenatal problems, effects on fertility, shortening of life, and
cataracts of the eye (Doull et al, 1980)71. It should be noted that the amount of radioactivity to which the
public is exposed during routine operation of nuclear plants is generally not thought sufficient to contribute
to these problems. Radioactive emissions settling on agricultural areas can be carried to a wider
population through farm products such as milk. Animals and plants exposed to radiation can also suffer
short and long-term damage.
EDB includes several source categories for radioactive emissions: Carbon-14, Iodine-131
(Elemental), Iodine-131 (Nonelemental)72, Noble Gases (including Krypton and Xenon), Radon,
and Tritium (H-3). At present, EDB contains emission coefficients for radioactive substances for
only a few nuclear technologies, and most have been derived from U.S. Department of Energy
documents.
Ammonia is a reduced73 form of nitrogen (NH3) widely used as an industrial feedstock,
agricultural fertilizer, and household cleaning agent. Ammonia is emitted in low concentrations by some
energy sector activities, including coal and oil combustion, oil refining, gasification of coal and biomass,
and geothermal energy conversion. EDB contains a limited number of ammonia emission coefficients for
some of these technologies. Man-made emissions of ammonia are much smaller, overall, than natural
emissions, which stem from anaerobic microbial activity in areas such as wetlands. Ammonia does not
typically remain in the atmosphere long, as it can react with oxygen in the atmosphere to form nitrogen
oxides, can be absorbed by water in the atmosphere, or can, in its electrically charged form (ammonium
ion, NH4+), combine with sulfates and other ions to form or add to particles in the atmosphere. When
inhaled, ammonia is an irritant to the respiratory system, but these effects are typically limited to
individuals working directly with the compound in poorly ventilated areas. Ammonia gas can injure
plants, but is rarely present, except in heavily polluted areas, in high enough concentrations to cause
damage (Freedman, 1989)74.
Thermal Emissions to the atmosphere include the radiation of heat and the release of steam (for
instance, from cooling towers) from energy sector activities. Thermal power plants, including both fossilfueled and nuclear facilities, produce approximately twice as much energy in the form of heat as they do in
the form of electricity. When cooling towers are used to dissipate heat from power plants, steam is
71 Pages 497-530.
72That is, iodine emitted as a compound with other elements.
73 “Reduced” and “Oxidized” are characteristics of molecules. Generally, more reduced species tend to be richer in hydrogen
atoms and have fewer oxygen atoms than oxidized species. For example, Methane, CH4, is the most reduced form of carbon,
while CO2 is one of the most oxidized forms.
74 Page 17.
Description of Major Environmental Effects Categories
61
typically released. These plumes of water vapor can change the local climate by increasing the local
humidity and producing shadowing (from the vapor plume), fogging, and icing under some conditions.
Excess water vapor can also accelerated the degradation of materials such as wood and metals, and can
increase mildew problems. When several very large power plants are located close to one another, a "heat
island" may be created that has the potential to disrupt circulation patterns in the local atmosphere.
Thermal emissions can be estimated fairly easily for most types of power plants, but at present there are no
emission factors in this category in EDB.
3.3 Water Effluents
Emissions of pollutants to bodies of water -- from ponds and streams to lakes, rivers, and oceans -are covered by a number of emission categories in EDB, though at present there are relatively few emission
factors for these “effects”. Those factors that are presently available are principally derived from U.S.
Department of Energy and World Health Organization documents. In general, emissions to water are most
likely to originate in energy transforming installations such as oil refineries, petroleum wells, coal mines, or
ethanol production facilities. Water effluents can also be created by aqueous emissions from the cleaning of
large fuel combustion facilities such as boilers75. Water effluents are typically measured in mass units,
with the exception of radioactive emissions, which are measured in units of radiation loadings. Brief
descriptions of the categories of water emissions covered in EDB, and their environmental impacts, are
provided below.
The emissions of Solids to bodies of water are described in two EDB categories. Suspended
solids are materials that mixed into water but not dissolved, such as slurries of mud, sand, ash, or other
particles, while Dissolved solids include salts and other materials in solution in effluents and in bodies of
water receiving the pollutants. Suspended solids reduce the visibility and the penetration of sunlight into
water, potentially affecting the behavior of fish and other species, and reducing the productivity of marine
and aquatic plants. Depending on the nature of the suspended material, suspended solids can also affect
water chemistry, as can dissolved solids. Both types of water emissions can affect humans through their
impact on drinking water quality, and on the quality of water used for recreation and industrial purposes.
Oxygen Demand is a measure of the amount of oxygen would be required by aquatic microbes to
degrade the organic material present in a water sample. Two measures of oxygen demand are Biochemical
oxygen demand (BOD) and Chemical oxygen demand (COD), which vary primarily by the laboratory
methods used to measure them76. Energy-sector sources of oxygen-demanding effluents include
petroleum refineries and fuel-alcohol production facilities. The effect of effluents which raise BOD and
COD is (depending on the types of organic matter present) to decrease the amount of oxygen available for
aquatic animals by increasing the demand for oxygen by microorganisms in the water that degrade the
organic matter. In extreme circumstances, as in rivers and lakes heavily polluted with sewage and/or
industrial effluents, the amount of oxygen in the water can fall to zero (anoxic conditions) resulting in the
75"Boiler blowdown" solutions, which contain minerals cleaned from boiler tubes, are an example here.
76Biochemical oxygen demand is measured by placing a sample in an incubation bottle with a "seed" culture of bacteria, and
measuring the dissolved oxygen content of the water before and after an incubation period, often five days (BOD5). Chemical
oxygen demand is measured by subjecting a water sample to strong chemical oxidants (potassium dichromate and sulfuric
acid); the COD of the sample is proportional to the amount of potassium dichromate used to reach a point at which an indicator
reagent changes color. BOD and COD values of the same sample can differ depending on the constitution of the sample,
including the types of organic and inorganic matter present. See Standard Methods for the Examination of Water and
Wastewater (American Public Health Association, Washington D.C., USA; reissued periodically) for a description of these
tests.
62
A Guide to Environmental Analysis For Energy Planners
death of most larger aquatic flora and fauna. Oxygen demanding effluents can also adversely affect water
used for drinking, irrigation, industrial processes, fishing and recreation.
A category for Organic Carbon effluents to water is provided in EDB. This is another way
(along with BOD and COD) of measuring the input of organic matter to aquatic ecosystems. With the
exception of toxic hydrocarbon species that may be included in emissions in this class, the effects of
organic carbon emissions will be similar to those described for the oxygen demand categories, above.
Oil and Grease emissions to water can come from petroleum extraction and transport activities
(such as oil tankers) or from the operation of energy-using devices such as automobiles. Oil and grease
can foul the surface of the water, injuring or killing aquatic and marine birds and mammals, as well as fish
and other organisms. Heavier oils can sink to the bottom and pollute sediments, harming shellfish and
other bottom-dwelling plants and animals. Some components of oil and grease emissions are toxic
hydrocarbons that become dissolved in the water and are taken up by aquatic and marine organisms,
causing a variety of impacts. Oil and oil products can also contain heavy metals, which have their own
toxic effects (as noted above; Freedman, 1989)77.
Sulfates are produced by a number of processes, including the "wet" scrubbing of boiler stack
gases to remove sulfur oxides, and the cleaning of boilers to remove sulfate-containing "scale". Addition
of sulfates change water chemistry, sometimes resulting in changes in species compositions. Water high in
sulfates must often be treated before use as drinking water or in industrial processes.
EDB includes effects categories for several different types of emissions of Metals to water. The
species covered are Cadmium, Chromium, Copper, Iron, Mercury, and Zinc. Energy sector activities
that can produce these emissions include oil refining, oil and coal extraction, and coal processing, though
other industrial activities (metals refining, tanning of animal skins) probably release larger quantities of
these effluents to water bodies than the energy-related sources. The health and environmental effects of
many of these metals were covered under Air Emissions, above, though water-borne metals pose slightly
different hazards, in some cases, than emissions to the air. The potential environmental impacts of the
metals not covered earlier (copper and iron) are described below.
Copper (Cu) is familiar as the principal metal used in electrical conductors (wires), and in many
other uses. In high enough concentrations, copper in aqueous environments can kill algae (in
some cases it is used for this purpose in water purification), thus affecting the basis of the aquatic
food chain. Though copper is an essential nutrient for some organisms, such as shellfish, fish are
sensitive to copper, as are animals such as sheep and cattle, in which copper can cause blood and
liver disorders. In humans high doses of copper can cause acute poisoning, the symptoms of
which include vomiting, jaundice, low blood pressure, and coma (Doull et al, 1980)78.
Iron (Fe) is an essential nutrient for humans and many other animals, being a key element in the
blood-cell protein hemoglobin, among its other physiological functions. The symptoms of acute
iron poisoning in humans include digestive system abnormalities, neurological problems including
coma, and possible jaundice. A few diseases are attributed to excess iron in the diet (chronic iron
poisoning), including "hemochromatosis" which results in abnormal skin pigmentation and liver,
spleen, and bone marrow abnormalities (Doull et al, 1980)79.
77 Chapter 6.
78 Pages 443-444.
79 Pages 445-447.
Description of Major Environmental Effects Categories
63
Salts is a general EDB category that can encompass a number of chemicals, including sulfates,
chlorides, nitrates, and others, that are soluble in water, that is, they dissolve to yield anions (negativelycharged ions) and cations (positively-charged ions) in solution. Sodium chloride (NaCl), commonly used
as table salt, is an example, being formed of a sodium ion Na+) and a chloride ion (Cl-). The amount of
salt present in solution is a general indicator of water quality in fresh waters. Salts affect aquatic
ecosystems in different ways, depending on the species present and the concentrations. Some species have
rather narrow ranges of salt tolerance, and are adversely affected when average concentrations rise above
(or below) a certain level. As salt concentrations increase, water may have to be treated or may be unfit
for human uses such as irrigation or drinking water.
EDB provides separate categories for Nitrates and Phosphates, which are classes of salts that
have the nitrate (NO32-) and phosphate (PO43-) ions as their respective anions. As salts, excessive levels of
nitrates in aquatic environments can affect water chemistry and the ability of different organisms to
survive, but it is nitrate’s activity as a fertilizer that is probably most of concern to the environment.
Nitrates and phosphates are used widely as nutrient amendments for terrestrial agriculture, so it is not
surprising that they promote the growth of algae and other aquatic plants. This increased productivity in
lakes and other bodies of water is called eutrophication. In the short run, increased algal growth helps
provide more oxygen and food for other aquatic species, but can also change the structure of aquatic
habitats, which can change species compositions. Potential adverse effects of eutrophication also include
unwanted "blooms" of algae that are unpalatable to fish and other herbivores, produce toxic substances, or
impart an unpleasant taste or odor to water. In extreme cases, massive blooms of algae can die off, and
the resulting oxygen demand (from the bacteria that degrade the dead algae) can result in periods of oxygen
depletion, which can result in fish kills and/or the evolution of noxious gasses such as hydrogen sulfide
(Freedman, 1989)80.
Chlorides are also a class of salts, and include sodium chloride, the most abundant salt in
seawater. The general effects of chlorides on the environment are as described above for salts.
Ammonia is readily dissolved in water. In sufficient concentrations, it can change water
chemistry by modifying (increasing) the pH. In addition, ammonia, when converted to ammonium ion, can
act as a nitrogen fertilizer to stimulate the growth of algae and aquatic plants, and can thus contribute to
eutrophication. Process wastewaters from petroleum refineries contain ammonia.
Cyanide (CN-) is a notorious poison toxic to humans and other organisms. Cyanide interferes
with the body's ability to utilize oxygen resulting, in extreme cases, in respiratory and circulatory failure.
Radioactive emissions to water have the same types of effects on aquatic and marine ecosystems
as they have on terrestrial ecosystems (see text above on radioactive air emissions), though some
radioactive particles will not travel as far in water as they do in air. EDB provides categories for
emissions of Tritium and of Activation and Fission Products, which are released in small quantities by
operating nuclear reactors, and have been released in larger quantities during accidents.
Thermal (heat) emissions to water, expressed in terms of energy, are produced by power plants
that discharge waste heat into rivers, lakes, or oceans. If the heat is released in such a way as to
significantly raise the temperature of the receiving body of water (and a rise of only a degree or so can be
significant, it can alter the composition of aquatic and marine ecosystems in favor of those that thrive in
80 Chapter 7.
64
A Guide to Environmental Analysis For Energy Planners
warmer waters. These warmer-water species are often less commercially desirable. In addition, thermal
emissions to water can lower levels of dissolved oxygen81, which can have a negative impact on fish and
other organisms (Ehrlich et al, 1977)82.
3.4 Solid Wastes
Several different categories for solid waste emissions are provided in EDB, but, as with water
emission, there are at present relatively few emission coefficients for these categories. Most of the
existing emission factors are derived from U.S. Department of Energy documents. EDB provides a
category for Total solid wastes of all types, plus several specific categories, as described below.
Mining Wastes, as the name implies, are solid wastes from mining operations, including such
energy-sector activities as the mining and processing of coal and of oil shale. EDB contains an emission
category for Inert mining wastes, that is, those materials that are not likely to react with air or precipitation
or to be mobile in the environment. Though their toxicity may be low, piles of inert mining wastes by their
physical nature change landscapes and thus the environment, potentially resulting in the displacement of
animal species, changes in vegetation (mining wastes are not usually particularly fertile substrates for plant
growth) and/or aesthetic impacts.
An environmental effluent of considerable importance, particularly for large boilers and other types
of facilities fueled with solid fuels (especially coal) and heavy oils83, is Ash84. There are two important
types of ash emissions from fuel combustion. Bottom ash remains in the boiler, oven, furnace, or stove
after fuel combustion is complete. Fly ash is particulate matter that is captured by pollution-control
equipment such as cyclone collectors and fabric filters (see footnote reference for sources describing
pollution control options). These two effluent categories are combined, at present, in a single Total ash
category. Beyond the physical effects of piles of ash on landscapes and on ecosystems, ash from coal and
oil combustion contains heavy metals, toxic organic compounds, and other potentially damaging substances
that can leach (that is, be dissolved in rainwater and flow out of the pile) out of ash disposal sites and
potentially affect ecosystems. If piles of ash are left uncovered, wind can blow smaller ash particles into
the air, where their potential effects are those noted for air emissions of particulates. Disposal of ash is
also an economic problem, particularly in countries where landfill space is scarce, where ash is defined as a
hazardous waste, or where ash must be transported a long distance for disposal.
Scrubber Sludge is an effluent of some concern for coal-fired industrial and electricity-generation
equipment. A scrubber is a device in which exhaust gasses pass through (typically) a solution of a
chemical such as calcium carbonate (limestone) in water. This process "scrubs" sulfur oxides and other
components from the exhaust gas stream, and produces a sludge containing calcium sulfate, ash particles,
and other chemicals. Some of these compounds can leach from storage areas into the environment,
potentially contaminating surface and ground waters.
81 This is both a physical phenomenon, as oxygen is less soluble in warmer waters, and a biological one, as higher temperature
promotes the growth of microorganisms, which then take up oxygen faster.
82 Page 670.
83The combustion of wood and other biomass fuels also yield varying amounts of ash, but their volume per unit energy is
generally lower than for coal combustion, and the concentration of potentially toxic substances in the ash is also lower.
84Coal ash may also pose an environmental hazard in countries where coal is widely used as a domestic cooking and heating
fuel.
Description of Major Environmental Effects Categories
65
Radioactive solid wastes are of a number of types. Most radioactive wastes are created during the
operation or decommissioning of nuclear plants, or during the mining, refining, and fabrication of nuclear
materials used for reactor fuels or weapons. A small amount of low-level waste is also generate by uses of
radioactive compounds for medical, industrial, and research purposes. EDB currently includes two effects
categories for low-level radioactive wastes, one expressed in terms of radiation loadings (Curies) and the
other in terms of waste Volume. The former category provides a measure of the radiological hazard of the
waste, while the latter gives an idea of the storage/disposal volume that would be required per unit energy
provided. Low-level wastes contain relatively small amounts of radioactivity, and the risk of human health
effects or environmental damage from these wastes are low if the wastes are properly disposed of. Lowlevel waste disposal facilities are, however, expensive to build and difficult to procure locations for, thus
they are of significant concern from a social and economic point of view. High-level radioactive wastes,
with large amounts of radioactivity per unit volume, are even more difficult to dispose of in a safe manner.
Storage facilities for these wastes must be designed to last up to tens of thousands of years, withstand
seismic activity, and keep wastes completely contained far into an uncertain future. The siting of high-level
nuclear waste sites has proven extremely difficult in the United States due to concerns over groundwater
contamination and other environmental issues, as well as social concerns. The latter include concerns as to
the fairness of siting waste facilities in areas, generally with very low population densities, that have had
few of the benefits of the electricity generated using the nuclear fuels, and issues of intergenerational
equity.
3.5 Occupational Health and Safety Effects
EDB includes several categories for direct occupational health and safety impacts. These are
Deaths, Injuries, and Work Days Lost. In each case, the unit of measure for the impact coefficient in
EDB is in numbers, so, for example, the deaths coefficient for coal mining would be expressed in number
of deaths per tonne coal mined, and so on for injuries and work-days lost. The energy-sector activities that
are of the most concern from an occupational health and safety standpoint are typically fossil-fuel
extraction and processing technologies such as oil and gas production and refining, coal mining. The
mining and processing of nuclear fuels, generation of nuclear power, and harvesting of biomass fuels can
also be of concern from an occupational health and safety standpoint. EDB includes a limited number of
coefficients for these effects, taken from a combination of U.S. Department of Energy, World Health
Organization, and other documents from the international literature. Occupational deaths, injuries and lost
work-days from energy sector activities can have social and economic impacts beyond those on the
individuals affected through their effect on families, on work force productivity, and on the perception of
the social costs of certain energy resources.
3.6 Other Effects
As noted in the introduction to this chapter, there are a number of important emissions and impacts
of energy use and energy conversion systems that have not yet been included in EDB. In some cases,
generic factors (or ranges of factors) for these emissions and impacts are scheduled for inclusion in later
versions of EDB. In other cases, it will continue to be up to you, the planner, to include these impacts in
your analyses as appropriate. Some of the emissions and impacts not now covered in EDB include:
•
The amount of land used by energy facilities. This would include the sites occupied by fossilfueled power plants, the reservoir areas of hydroelectric facilities, the area occupied by solar
66
A Guide to Environmental Analysis For Energy Planners
photovoltaic panels, and the area used for nuclear and other waste facilities. Note that there are
significant differences between some of these types of land use: land used for photovoltaic panels,
for example, can often be fairly easily reclaimed for other uses, while land used for nuclear waste
facilities may be restricted to that use indefinitely.
•
The use of water in energy facilities. Water use includes water consumed, that is, rendered
unavailable for other uses, and water that is merely used temporarily, then returned to the water
supply in a form suitable for re-use.
•
The use of materials, such as cement, steel and other metals, plastics, and wood, in the
construction of energy facilities and products. The use of these materials may have direct or
indirect impacts of their own, and should be considered in a true full-fuel-cycle analysis.
•
Noise emissions by fuel-producing and -using devices. Noise emissions must be defined at a
specified distance from the source.
•
The frequency and results (deaths, injuries, illnesses) of major catastrophic accidents, such as dam
failures or nuclear mishaps, as well as more minor (but possibly more frequent) incidents.
•
Aesthetic considerations.
•
Impacts on biodiversity.
This chapter has described the environmental loadings that are currently included in EDB, and
briefly discussed some of those that are not. In conjunction with the information provided in Chapter 2,
which covered the general relationships between energy technologies and environmental impacts, the
material presented here provides essential background for the task of estimating the potential range of
environmental impacts associated with alternative energy development options. In the next chapter we
present an overview of how the loadings included in the EDB have been estimated. It is important for
analysts to clearly understand the genesis of these loading figures so that they may be used appropriately.
Environmental Loading Data: Sources, Estimation, and Uncertainty
67
4. Environmental Loading Data: Sources, Estimation, and Uncertainty
4.1 Introduction
The preceding sections of this manual introduced some of the broader issues in energy-environment
analysis (Section 2), and provided a guide the environmental loading categories found in the EDB (Section
3). In this section, we focus on the methods and data used to estimate loadings for various energy
activities. These data are the heart of EDB itself, namely the factors for air, water, and solid waste
emissions, for on-site health and safety impacts, and for resource use or degradation. The bulk of this
section will focus on the first of these three categories: the emission factors that constitute the majority of
"generalizable" data and of EDB entries. Methods used to estimate on-site health and safety impacts are
also mentioned. We discuss how to determine the appropriate form of emission factors for a given type of
analysis, how emission factors are measured, and what to do in instances where emission factors are not
available (in EDB or elsewhere) for a particular technology. We also discuss the many uncertainties,
errors, and limits to applicability of emission factors, some of the categories of emission factors that are
most sensitive to local conditions, and some of the major sources of emission factors used to create the core
database of EDB.85
4.2 Emission Factors: What they are and where they come from
Emission factors or coefficients (we use the terms interchangeably) describe the quantity of a
pollutant that is released per unit of fuel consumed, produced, or lost. In EDB terminology, emission
factors describe the relationship between an energy activity or Source category (e.g a type of automobile
or electricity generating plant) and an Effect category (a specific pollutant). A few sample emission
factors, together with units and descriptions of what they mean, are given in table 4.1, below.
85 A full listing can be found in “Environmental Data Base (EDB): A Listing of Core Database Coefficients”, SEI-B, May
1995.
68
A Guide to Environmental Analysis For Energy Planners
Table 4.1: Sample Coefficients From EDB
Emission
Effect
Source
Factor
Units
Category
Category
Description
2550
kg/tonne
Air/Carbon
Coal-fired
There are 2550 kg of carbon dioxide released to the
Dioxide
Stove
atmosphere per tonne of coal burned in a household stove.
Air/Hydrogen
Geothermal
There are 1.24 grams of hydrogen sulfide released to the air
Sulfide
Power Plant
per GJ of geothermal energy used by a power plant.
Solid
Ethanol
Waste/Total
Production--
1.24
38.1
gm/GJ
gm/liter
There are 38.1 grams of solid wastes produced for each liter of
ethanol produced using corn as the biomass feedstock.
Corn Based
On-Site Impact
Effect
Source
Factor
Units
Category
Category
Description
1.16E-8
deaths/bbl
Occupational
Oil Production-
There are 1.16 x 10 accidental worker deaths per barrel of
H&S/Deaths
-US Onshore
crude oil output from an oil production facility, or 116 deaths
-8
for every billion barrels of oil produced.
NOTE: In EDB and associated documents, the exponent or power of ten follows the letter "E". "E-9" is
shorthand for "10-9". Thus, 1.16E-8 = 1.16 x 10-8 = 1.16 x .00000001 = .0000000116.
Environmental Loading Data: Sources, Estimation, and Uncertainty
69
Box 4.1 Fuel Chain Analysis
Related to the determination of cause and effect in the relationship between energy activities and emissions factors is
the consideration of full fuel chain analysis. When people use energy--for example when we turn on a light bulb, drive to work
in a car, or cook our dinner--we are finishing a chain of related activities that makes energy use possible. This chain of
activities, sometimes called a fuel chain or cycle, may be short as burning fuelwood just collected nearby, or as long as:
Locating oil deposit ---> Drilling oil well ---> Extracting crude oil ---> Transporting crude to refinery ---> Refining oil into
gasoline --->Transporting to filling station ---> Filling cars with fuel ---> Driving
At each point along these chains of activities, the various energy technologies used can have impacts on the
environment. These impacts can be in the form of pollutant emissions to the air, water, or soil, can affect--either directly or
indirectly--human or animal health and safety, can be physical or chemical changes that alter the way that the environment
functions, or can be a combination of many different individual effects.
When comparing energy options, it is important to consider environmental impacts beyond those of fuel production
and use, to the "upstream" and "downstream" effects. For instance, an analysis of the environmental costs and benefits of
substituting electricity for, say biomass use in household stoves would be incomplete if it did not consider, in addition to the
impacts of fuel consumption at the point of end use, the impacts of burning fuel (if applicable) to generate electricity, the
impacts of the electricity transmission and distribution system, and the host of resource production impacts: oil production, oil
spills, coal/peat mining, etc. A different list of potential impacts will be applicable to the biomass alternative, in this example.
The point here is that unless the environmental impacts of the full fuel chain are considered--qualitatively and/or quantitatively-there is a grave risk of overlooking a set of significant impacts by considering only a subset of the system that makes energy
use possible.
Leaving aside consideration of economic impacts, let us assume that we are comparing the use of electric household
stove with biomass-fired stoves, and, further, that the electricity will come from coal-burning power plants and the biomass is
locally produced in a sustainable fashion. If the borders of our comparison between these alternatives are drawn tightly,
encompassing only the fuel end use, then the electric stove looks like a good bet: it is efficient, requires no fuel harvesting or
transport on the part of the household, and produces no emissions. The biomass stove, in contrast, requires the household to
find, harvest, and carry the biomass back to the house, and as it burns producing, in varying amounts depending on the type of
fuel, stove and firing conditions used (see section 4.5), produces a host of potentially hazardous atmospheric emissions.
When we expand our window of analysis to encompass more of the fuel cycle, the comparison doesn't look quite so one-sided.
Building a coal-fired power plant requires land to be committed for use as the power plant site for the life of the installation and
perhaps longer, while land used to grow biomass may be used for other purposes, such as farming and pasture. The power
plant itself is a source of atmospheric emissions, including direct and indirect greenhouse gasses, solid wastes, and sometimes
liquid wastes as well, while sustainable production of biomass fuels will typically produce fewer emissions. Coal plants require
fuel, which must be mined. Both coal production and coal transport have attendant impacts on the environment and on human
health and safety. Electricity transmission and distribution lines are associated with yet another set of environmental concerns.
Thus drawing the lines of analysis to encompass more of the fuel cycle yields a radically different picture than an initial look at
just the end-use impacts of fuel use.
LEAP and EDB are set up to allow the evaluation of fuel cycle impacts. Furthermore, as part of a recent UNEP/SEI
collaboration, a new LEAP Fuel Chain program was developed and is available as part of LEAP 95 and subsequent versions. A
report describing fuel chain analyses in two case study countries, Venezuela and Sri Lanka, is available from SEI-B.86
86 SEI/UNEP Fuel Chain Project: Final Report, SEI-B, May 1995.
70
A Guide to Environmental Analysis For Energy Planners
Emission factors are measured and/or estimated numbers that relate effects to sources. Emission
factors are thus numbers that allow the energy/environment planner to estimate quantities of emissions and
other environmental effects or impacts associated with activities such as the tonnes of fuel burned using
coal stoves, or the barrels of oil passing through a refinery.
4.2.1 Who Collects Emission Factors, and Why?
Emission factors are determined by empirical measurement or by various estimation techniques.
Some of the methods used are discussed later in this section. Emission factors are typically measured or
estimated by researchers working for governmental or international agencies, industrial firms, universities,
or research institutes. The motivations for collecting emission factor data are as diverse as the people who
collect them.
1. Government agencies, such as the Environmental Protection Agency in the United States, collect
emission factors (or contract with private firms or academic researchers to do the collection) for several
reasons. First, many governmental agencies wish to establish inventories of pollutant emissions or
other environmental effects. These inventories are lists of the quantities of pollutants emitted,
sometimes broken down by source location and/or by the economic sector and sub-sector. The
inventories are calculated by multiplying emission coefficients by the level of corresponding activity
(coal combustion, for example) in the location or sector under study. This is essentially the same
approach applied when LEAP and EDB are used together to estimate emissions. Emission factors,
and the inventories produced using emission factors, are used to establish baselines for monitoring of
environmental conditions, for the design of pollution reduction programs, as tools to identify areas or
sectors with specific environmental needs or opportunities, and as inputs to environmental impact
models. Impact models use emission factors and emission inventories to estimate the impacts of
emissions on, for example, air or water quality. Periodic inventories show the trends of environmental
emissions over time, which is useful for the planning of future government regulations or investments.
Emission factors are also used for standard setting and for checking compliance with performance
standards of energy technologies, such as power plants and automobiles. In many countries,
automobiles must meet certain standards of emissions per mile traveled, and emission factors for the
various types of automobiles are periodically measured and checked to assure that manufacturers are
complying with regulations.
2. Some industrial firms also measure and estimate pollutant emissions to monitor their facilities’
compliance with governmental regulations. They may also collect such data in order to study
production process efficiencies and/or to investigate opportunities to make production processes
cleaner. Manufacturers of emission reduction equipment or low-emission technologies seeking to
promote their wares may also collect and disseminate data on emission factors.
3. University-based researchers are another source of information on emission factors. Most academic
work is done in the engineering and environmental science disciplines. It includes activities such as
measuring the emissions from prototype engines or boilers, testing equipment for emissions using
different fuels, firing rates (the rates at which fuels are burned), and combustion conditions, and testing
new pollution-reduction technologies. University-based researchers are also responsible for many of
the emission factor estimates for household stoves used in the developing world.
4. International and intergovernmental organizations, such as the United Nations Environment
Program (UNEP) and the World Health Organization, measure and collect emission factors to assess
the extent and severity of global and regional environmental problems. (GEMS, Environmental Data
Environmental Loading Data: Sources, Estimation, and Uncertainty
71
Report) These organizations also provide databases, reports, and guides as a service to planners and
decision makers in their member countries. EDB itself is the product of a collaborative project between
SEI and UNEP; the WHO's Management and Control of the Environment report provides another
useful compendium of emission factors and modeling techniques. The Intergovernmental Panel on
Climate Change (IPCC) collects and disseminates information on emission factors for greenhouse
gases, including greenhouse gas emissions from the energy sector. Some of these emission factors-often based on factors from one of the sources above--are presented in the Greenhouse Gas Inventory
Workbook: IPCC Guidelines for National Greenhouse Gas Inventories, published jointly by the IPCC
and the Organisation for Economic Cooperation and Development (OECD).
4.3 The Cause-and-Effect Relationship in Emission Factors
An emission factor links the amount of a quantity you know, e.g. the liters of diesel fuel used by a
motorcycle, to a quantity you would like to know, e.g. the emissions of particulate matter by that vehicle.
This presupposes a direct linear relationship between the two quantities, and that the former causes the
latter. Often there are also indirect links between emissions and the energy activity, which can be of
relatively major or minor importance. Therefore, before proceeding to use or enter emission factor data, it
is important to examine the nature of the relationship between the source and the emissions of concern and
determine how the emissions are a direct and/or indirect result of the energy activity. In the case of
motorcycle emissions for example, the relationship between the liters of fuel consumed and the emissions of
pollutants is both direct and indirect. While some hydrocarbons are emitted from the tailpipe, and are thus
a fairly predictable direct function of the amount of fuel consumed, other hydrocarbons are emitted as oil in
the crankcase evaporates or is broken down by the high temperatures of engine operation. These emissions
(known as "crankcase emissions") are a function of how the vehicle is used, but not necessarily how much
fuel is consumed. Another class of hydrocarbon emissions ("evaporative emissions") result as fuel in the
gas tank evaporates to the atmosphere. Evaporative emissions may be a function mostly of the temperature
at which the motorcycle is stored. These distinct types of hydrocarbon releases can all be included in a
coefficient describing overall hydrocarbon emissions from motorcycles, but to do so a number of
assumptions must be made, including the average duty cycle (the number of miles per trip, how fast the
motorcycle travels, and how often it is used) and the average temperature at which the vehicle is stored and
operated. When this level of detail is considered appropriate all necessary assumptions should be clearly
documented.
A second example is a coal fired smelting process, which refines raw materials such as copper ore
into primary metals such as copper. While some of the emissions from this process are a direct function of
the amount of coal consumed, others, such as emissions of particular trace metals (say, vanadium), are
more strongly a function of the quantity of copper ore processed and the composition of the ore itself. As
a consequence, it would be erroneous to estimate a smelting process emission factor for vanadium that is
solely dependent upon the tonnes of coal consumed. Similarly, the total emissions of carbon dioxide from
the manufacturing of cement is not a straightforward function of the fuel consumed in the manufacturing
process. The processing of limestone, typically a crucial raw material, produces a great quantity of CO2
independent of fuel consumption. As a final example the emissions from a petroleum refinery depend not
only on the fuel consumed by the various boilers and burners used, but on the types and relative amounts of
the different petroleum products the refinery produces as well as on the types of crude oil and other
substances used as raw materials in the refining process. Generic emission factors for such installations
should therefore be used with caution.
72
A Guide to Environmental Analysis For Energy Planners
4.4 Determining the Appropriate Units for Emission Factors
Even when emissions follow directly from the energy use of a specific activity for which data is
available, emission factors are often not available in exactly the form needed for analysis. Before applying
emission factors in a planning context, entering emission factors into EDB, or developing emission factors
from test data, it is important to check the form of an emission factor, so that the units unambiguously
match those of the energy activity whose emissions or impacts are being estimated.
When specifying emission factors in EDB, it is necessary to distinguish between the actual units
used, and the type of units used. For example, there are many different ways to express units of the mass
type; milligrams, grams, kilograms or tonnes are examples of international units, while pounds and "short
tons" (2000 pounds) are English units. Conversion between these units is a relatively simple matter, and is
accomplished automatically in EDB, as long as the units are contained in EDB's list of common units. The
type of unit is a more important choice, as noted below.
In most instances, selecting the type of numerator unit for an emission factor will be fairly
straightforward. Emissions to air and water, are typically measured (with the exception of radioactive
emissions) in mass units (e.g. grams, kilograms, or pounds), likewise solid wastes. The numerator unit for
occupational health and safety is dictated by the type of impact measured (injuries, deaths, lost work days).
In other cases emissions or effects are measured in clear but (from the standpoint of estimating emission
factors) incomplete units as when pollutant concentrations are measured instead of masses. If, for
example, methane emissions from combustion of biomass in a wood stove are reported as 3.2 ppm (partsper-million), then you know the amount of methane relative to the amount of exhaust gas leaving the stove,
but you do not know, without additional information (namely the amount of exhaust gas released per unit
fuel, the temperature of the gas, and/or the amount of oxygen present in the gas), the amount of methane
emitted per unit fuel burned. Other difficulties in handling numerator units for emission factors arise for
radioactive emissions. The most basic unit of radioactivity is the "Curie"" (Ci), which is equal to a certain
number of radioactive disintegrations per second. Other units commonly used, including the "rad" and the
"rem"87, depend on assumptions such as the distance an exposed person or animal is from the source of
radioactivity and the time of exposure, and thus must be evaluated carefully before being interpreted as
emission factor estimates for general use.
It is often also necessary to determine if the factor should be specified based on the energy or fuel
input or whether on the process or energy output. In general, emission factors based on energy input are
more widely applicable, since output-based factors depend critically on process efficiencies, which can vary
significantly.
The emissions of carbon monoxide from a wood cookstove, for example, could be measured as
grams of CO per kg of wood consumed in the stove, or in grams of CO per kilocalorie of heat energy
supplied to the cooking pot. Both forms are correct, but the emission factor based on input fuel is more
broadly applicable since, within limits, it can be applied to stoves that have different efficiencies from the
stove for which emissions were originally measured. In contrast, emission factors based on energy output
87The "rad" and "rem" are measures of the dose of radiation that a radioactive source delivers to an absorbing material (e.g.
human tissues). A rad is a measure of the amount of energy deposited per unit mass of the absorbing material, and is equal to
10-5 Joules deposited per gram of absorber. A "rem", or "Roentgen Equivalent Man" (after German scientist W.K. Roentgen,
the discoverer of x-rays) is equal to a rad times a factor called the relative biological equivalent, or RBE, which is a measure of
how much damage the form of radiation is likely to do to the biological tissue that absorbs it.
Environmental Loading Data: Sources, Estimation, and Uncertainty
73
would have to be accompanied by the efficiency of the stove in order to be properly interpreted and applied
to stoves of different efficiencies, since the amount of fuel used to produce a unit of output would differ.
Similarly, data on emissions from vehicles are often specified in unit weight of pollutant per unit distance
traveled: grams per kilometer or grams per mile. In order to estimate emissions based on fuel inputs,
assumptions on vehicle efficiency are needed (for example, liters of fuel used per kilometer traveled, or
gallons of fuel per mile). Assumptions on vehicle efficiencies and the calculation of emissions per unit of
fuel input are included for many of the transportation-sector emission factors in EDB.
For other types of energy-transforming devices, it may be more convenient to describe an emission
factor in terms of the energy or product output from the process. The production of crude oil is an
example. In general, the output of an oil well will be relatively easy to determine, thus it is natural to
specify emissions or impacts in terms of the barrels or tonnes of crude oil produced. Output-based
emission factors are also suited to processes such as coal mining, gas production, fuelwood collection, and
wood milling.
When reviewing documents containing emission factors, it is important to check whether the
factors are measured on the basis of energy input or output. This will, in part, determine whether they can
be used directly with energy data, or whether they will need to be modified. Quite often, emission factors
for power plants that use burnable fuels (such as biomass, oil, or coal) will be specified per GWhe, that is,
per Gigawatt-hour of electricity. If one were to specify emission factors for power plants per unit fuel
input, say, in EDB, it would be necessary to find or estimate the efficiency of the power plant. For it is
possible to convert an output-based emission factor of 1000 te CO2/ GWhe by applying an electricity
generation efficiency:
1000 te CO2/ GWhe * 0.34 GWhe/GWhfuel input = 340 te CO2/GWhfuel input,
or in Gigajoules (GJ):
340 te CO2/GWhfuel input / (3600 GJfuel input /GWhfuel input) = 0.094 te CO2/GJfuel input
In turn, this emission factor may need to be converted to indicate emissions per unit of physical input, such
as tonnes of coal or liters of diesel, as discussed below.
4.4.1 Physical vs. Energy Units
Choices also exist for the type of emission factor denominator unit. In EDB, users are encouraged
to enter emissions or impacts in physical, units, that is, emissions per unit mass or volume of fuel
consumed. Alternatively, factors may be entered with denominators of energy units, for example, kg of
nitrogen oxides emitted per GJ (gigajoule) of natural gas consumed. When making the choice between
physical and energy units the following questions should be considered:
1. Is the emission or impact likely to scale (grow or shrink) with the energy input to the process, or with
the physical input of fuels? This is an especially important distinction in instances where the energy
content of a particular fuel type can vary substantially per unit mass or volume. An example is sulfur
oxide (SOx) emissions per unit of coal consumed. Since SOx emissions typically depend on the
quantity of sulfur per unit mass in the fuel, expressing a coefficient for this pollutant in, for example,
kg of sulfur oxides per GJ of coal burned, could lead to errors if the energy or sulfur contents of the
coal being burned when the emission factor was measured are very different from the energy or sulfur
contents of the coal being considered. For example, say a coefficient indicates that 1.3 kg of SOx are
74
A Guide to Environmental Analysis For Energy Planners
emitted per GJ of coal consumed, and this coefficient was measured in an industrial boiler using coal
with an energy content of 30 GJ/tonne and containing 1% sulfur. If the coal in your area also contains
1% sulfur by weight, but its energy content is 15 GJ per tonne, then using the emission factor based on
energy units will understate the emissions of sulfur from combusting a tonne of coal by a factor of two.
Calculation Using Emission Factor in Energy Units:
1.3 kg/GJ * (1 tonne * 15 GJ/tonne) = 19.5 kg SOx
Calculation Using Emission Factor Converted to Physical Units:
(1.3 kg/GJ *30 GJ/tonne) * 1 tonne = 39 kg SOx
2.
Is it possible to describe the source of the emission or impact unambiguously, that is, in such a way
as it can be understood with no additional information, using physical units? For example, consider
a power station fueled with low-quality lignite coal. The emissions of nitrogen oxides to the air can
be measured per unit mass of lignite burned, but to do so would not allow you--unless other
information was supplied--to apply this emission factor to other coal-fired plants. This is because the
energy content of low-quality coal can vary considerably from country to country and even mine to
mine. This would be an instance where the denominator for your emission factors should be specified
in energy units.
In EDB, emission factors for all "Demand" categories (stoves, industrial boilers, automobiles,
furnaces, etc.) are specified per unit fuel input. There are general conventions as to which of the
"Transformation" (electricity generation facilities, coal mines, petroleum refineries, biomass harvesting,
etc.) categories have emission factors based on fuel input, and which are based on fuel output. When
creating a new category you have the option of which specification to use88. Table 4.2 shows the
input/output conventions used in entering the EDB core data
88In addition to input and output, you can, when setting up EDB Transformation categories, specify that emissions from a
Transformation process be proportional to losses of a fuel from that process. This option is typically used for technologies
such as natural gas pipelines, where emissions of substances such as methane are more accurately specified relative to the
amount of fuel lost during gas transportation, rather than the amount of gas entering or leaving the pipeline.
Environmental Loading Data: Sources, Estimation, and Uncertainty
75
Table 4.2:
Use of Physical or Energy Units for Emission Factors
LEAP
Appropriate
Emission factor
Sample Units
Program
Device
Unit Type
specified per unit:
Demand
End-use fuel-combustion equipment: coal,
Physical
Fuel input
kg CO/cubic meter gas
Energy
Solar input or heat
GJ thermal energy
output
emitted/GJ solar energy input
oil, natural gas
Demand
Solar Space/Water Heaters or Cookers
Trans.
Power plants burning coal, oil, natural gas
Physical
Fuel input
kg fly ash/tonne coal
Trans.
Geothermal, Hydroelectric, Nuclear, Solar
Energy
Fuel Input
Curies of radiation/GJ
Photovoltaic Power Plants
Trans.
Distribution Losses
nuclear heat input
Physical
Fuel Losses
kg VOC/liter of gasoline lost
during transport
Trans.
Ethanol, Biogas Production, Charcoal
Physical
Fuel Output
Production
Trans.
Coal, Oil, Natural Gas Production
kg suspended solids (liquid
waste)/liter ethanol produced
Energy
Fuel Output
kg hydrocarbons/bbl oil
output
4.5 Measurement and Estimation of Emission and Impact Factors
All of the emission and impact factors in EDB and in other references are derived from measured
quantities such as emissions for test devices, estimated based on fuel composition or other parameters,
calculated from available statistics, based on the judgment of researchers, or derived using a combination
of these techniques. An overview of some of the different approaches used to estimate emission factors is
given below.
4.5.1 Measurement techniques
Many of the pollutant emission factors found in the literature are derived from sample
measurements of emissions taken during tests of equipment. The types of equipment tested span the range
from wood stoves to nuclear power plants, and include technologies ranging from the experimental (such as
prototype automobiles or fuel-cell electricity generators) to the well-established. A variety of different
kinds of tests and monitoring systems are used, depending on the type of emissions being investigated and
the media--air, water, or solid wastes--to which pollutants are emitted.
Emissions of pollutants to the air and water are measured or monitored using two basic techniques.
The first is referred to as grab sampling in which, as the name implies, a sample of the gas leaving the
combustion chamber, smokestack, or exhaust pipe of the device being tested is "grabbed", or removed, into
a bottle, flask, or other gas-tight container. These samples may be evaluated within a few hours, or may
be reserved for later analysis. It should be noted, however, that different techniques for grab samples can
yield different results, even if you are starting with exactly the same sample. Pollutants and other gas
76
A Guide to Environmental Analysis For Energy Planners
constituents can be adsorbed to the walls of the sample container, or can react to yield a sample that, when
analyzed, is different from the sample actually taken. An extreme case of a pervasive sampling anomaly,
in this case one that caused a large number of emission factors to be called into question, was the error in
nitrous oxide sampling procedures described in Box 4.2 below. The second general method of empirically
measuring air pollutant emissions on-line monitoring. A sensor is placed in the stream of exhaust gasses (or
a part of the gas stream is routed through a sensing apparatus) and the sensor and an associated data
logging device take and record continuous measurements during the testing period.
Box 4.2: Problems in Sampling Techniques: The Case of N2O Grab Sampling
Until about 1988, measurements of nitrous oxide, or N2O --an important greenhouse gas (see
section 2)--were made by taking grab samples from the exhaust stacks of equipment such as boilers, and
evaluating them sometime later in the laboratory. This practice, however, was found to cause a
sampling error or "artifact". It turned out that in many samples, the (non- N2O) nitrogen oxides, sulfur
dioxide, and water vapor contained in the sample, were reacting in a complex manner to form far more
N2O than was originally present in the sample, sometimes 50 to 100-fold more. This caused estimates
of global emissions of nitrous oxide from the energy sector to be much higher, for a time, than is
probably the case. Global estimates of the emission of nitrous oxide from fossil fuel combustion have
recently been revised downward by a factor of between 10 and 30 (Levine, 1992).
Both types of sampling have advantages and disadvantages. Grab samples allow a centrallylocated laboratory to process a number of samples from different energy installations, devices, or areas,
assuring consistency in sample evaluation and cost savings relative to the installation and maintenance of
expensive and sophisticated monitors at many individual sites. Grab sampling can also be used in cases
where it would be technically infeasible to install an on-line monitoring device. Care must be taken,
however, that accepted sampling and storage methods are used, since, as noted above, changes in the
techniques used can drastically affect results. Also, samples taken must be representative of the air or
water effluent flows during normal operation.
On-line monitors are useful, particularly for large energy installations such as industrial boilers,
power plants, and refineries, but their use also requires care. The exhaust stack of a power plant, for
example, is an unforgiving environment where high temperatures, abrasive soot particles, and corrosive
gasses may rapidly degrade monitoring sensors or sampling equipment. If these devices are not checked
and calibrated (or replaced and calibrated) frequently, erroneous measurements can result. Note that
accurately calibrated equipment is also necessary for the measurement grab samples, but laboratory
environments (where the analytical devices used to process grab samples are typically found) are usually
less stressful to machinery than individual installations at boilers, power plants and similar facilities.
Identification and quantification of air pollutants monitored by both grab-sample and on-line
measurements rely on a set of analytical technologies. Some of these are described in Table 4.3.
Whatever method of measuring air emissions is used, additional data such as the rate at which fuel is being
used by the device (the firing rate), the volume of gas passing through the stack, the amount of oxygen in
the gas stream, and the temperature of the gas stream at the sampling point are required in order to relate
the measurement, which yields the concentration of pollutant constituents in the gas, to the mass of
pollutant released per unit fuel burned. Similarly, for aqueous e missions, the flow rate of liquid effluents
from a process, the relationship of the effluent flow rate to the rate of fuel combustion and the
concentration of the pollutants in the effluent, must be known, before an emission factor based on the unit
inputs or outputs can be estimated.Table 4.3:
Environmental Loading Data: Sources, Estimation, and Uncertainty
77
Methods For Measuring Air And Water Emissions
Method
Used for
Grab Sampling
Wide variety of air emissions, both air and water
Gas Chromatography
Wide variety of air emissions, both air and water
Mass Spectroscopy
Wide variety of air emissions, both air and water
Infra-red Absorption Spectroscopy
Wide variety of air emissions, both air and water
Ion-specific electrodes and meters
Pollutants in liquids, salts, acids, and bases
Liquid Chromatography
Pollutants in liquids, particularly organic emissions
Analytical Kits and Reagents
Various applications
Traditional "Wet Chemistry"
Water-borne pollutants, especially inorganic constituents
Solid waste emissions are typically measured using grab samples, which are subjected to one or
more of the analytical methods listed above. Radioactivity is often measured (on-line or in samples) with
"Geiger Counters" or similar devices that "count"--in the simplest monitors by giving off a sound-whenever a radioactive particle of a certain type hits the monitor's detector. The rate at which "counts"
occur indicates the extent to which the sample or area monitored is radioactive.
4.5.2 Emission Factors and Fuel Composition
A number of emission factors are estimated based primarily on fuel composition or on the way that
the fuel is burned, rather than on the strength of empirical measurements like those described above. This
is often true for emissions of carbon dioxide, sulfur oxides, and trace metals such as lead. EDB provides a
mechanism whereby an emission factor can be directly related to the carbon, sulfur, (as is applicable for
CO2 and SOx) nitrogen or moisture content of a fuel, allowing for the entry of the actual percentage (by
weight) of these elements in the fuel for which the emission factor was measured or estimated. For
emissions such as trace metals, this fuel composition option is unavailable, but it is important to enter the
fraction of the trace constituent (if known) as part of the documentation notes in order to inform others who
might use your data as to the basis of the estimated emission factor.
Good examples of estimates based upon fuel composition are estimated emissions to the air of
carbon dioxide (CO2) and sulfur oxides (SOx). When the sulfur and carbon in a fuel (coal, for example)
are burned, that is, react with oxygen in the air, these two oxidized (in this case, oxygen-containing)
compounds are produced. When combustion is reasonably complete virtually all of the carbon in the fuel
will be converted to carbon dioxide (usually about 98 to 99 percent for fossil fuels89). Likewise virtually
all of the sulfur in a fuel will typically be oxidized to SOx though some may remain as elemental sulfur (S)
in ash or in fly ash (the ash that leaves the combustion area in the exhaust gasses as tiny particles of soot).
Actual sulfur oxide emissions to the atmosphere may be modified by pollution control equipment. For
instance, a scrubber may capture 90 percent of the SOx leaving the combustion chamber of a boiler. In this
89One notable exception here are emissions from internal combustion engines, most frequently older cars and trucks. In some
cases emissions of the partially-oxidized product carbon monoxide (CO) can account for a substantial--though still not major-fraction of the total carbon in the fuel. It should be noted that Although CO is an important pollutant from the standpoint of
local air quality, the distinction between CO and CO2 emissions is of limited importance if you are estimating the emissions of
greenhouse gases, as CO is oxidized to CO2 in the atmosphere relatively quickly. The IPCC Greenhouse Gas Inventory
Workbook lists default factors for the incomplete oxidation of carbon in fossil fuels ranging from 1 percent for oil and oil
products to 2 percent (and higher) for coal (IPCC/OECD, 1993).
78
A Guide to Environmental Analysis For Energy Planners
case net emissions to the atmosphere would be 10 percent of the total SOx leaving the boiler. Examples of
how emission factors for carbon dioxide and sulfur oxides can be calculated, based on a knowledge of the
composition of the fuel, are given in Boxes 4.3 and 4.4 below, and Box 4.5 gives additional detail on how
the CO2 emission factors in EDB were calculated.
Box 4.3: Sample Calculation of CO2 Emission Coefficient: Kerosene Stove
Initial Data and Assumptions:
• Kerosene assumed to be 85% carbon by weight.
• Estimated fraction of carbon oxidized: 99%
• Ratio of weight of CO2 to C: 44/12 (molecular weight of CO2)/(molecular weight of C)
Calculation:
0.85 kg C/kg fuel x.99 kg C emitted/kg C fuel x 44/12 kg CO2/kg C = 3.09 kg CO2/kg fuel, or
3.09 kg CO2/kg fuel x 0.81 kg/liter (density of fuel) = 2.5 kg CO2/liter kerosene.
Box 4.4: Sample Calculation of SOx Emission Coefficient: Industrial Boiler
Initial Data and Assumptions:
• Sulfur content of coal assumed to be 3% (by weight).
• Estimated fraction of sulfur emitted as SOx: 95%
• Ratio of weight of SOx to S: 64/32 (molecular weight of SO2)/(molecular weight of S)
• Efficiency of SOx scrubbing system: 90%
Calculation:
0.03 kg S/kg fuel x .95 kg S emitted/kg S in fuel x 64/32 kg SOx/kg S
x (1 - .9) SOx not scrubbed/total SOx = 0.00285 kg (2.85 gm) SOx/kg coal.
Calculations of emission coefficients based on fuel composition are useful when you lack an
emission coefficient corresponding to a specific end-use device, but want to include at least approximate
emissions from that device in emissions accounts. For example, few measured emission factors for
kerosene lamps are available, but emissions of CO2 from these devices--which are important household
appliances in many parts of the world--can be estimated fairly readily. The same approach is sometimes
useful for other types of emissions, including emissions of ash from boilers fired with solid fuels (coal,
wood, municipal solid wastes) or heavy oils, and the emissions of trace metals such as mercury, cadmium,
or lead (found in coal). Like CO2 and SOx, these emissions of these substances are often a fairly
straightforward function of fuel composition.
Environmental Loading Data: Sources, Estimation, and Uncertainty
79
Box 4.5: Preparation of CO2 Coefficients for EDB
The following procedure was used to establish a consistent set of coefficients for carbon dioxide
emissions in EDB. First, a set of carbon contents by fuel was compiled from the literature90 and, in
some cases, by calculations based on fuel molecular weights. Next, these carbon fractions were
multiplied by the ratio of CO2 to carbon molecular weights (44/12) and by an assumed average fraction
of fuel that goes through burners unoxidized. The “unburned” fraction of fuel carbon (assumed to be
primarily emitted as soot and ash) was estimated to be 1.0 percent for each type of fuel (that is, 99
percent of the carbon was assumed to be combusted). While this assumption is consistent with literature
estimates (e.g. Grubb, ibid.; OECD, 1991, Background Document for the February, 1991 Workshop on
Emissions Methodology, Chapter 2: "Emissions from Energy Production and Consumption"), very little
recent empirical work appears to have been done to quantify the fraction of carbon left unoxidized in soot
and ash after fuel combustion. For types of fuel use (e.g. automobiles, wood stoves) where CO
emissions represent a significant (c. 0.5 percent or greater) fraction of total carbon emissions, the
fraction of carbon emitted as carbon monoxide was subtracted from the CO2 emission coefficient. This
avoids the problem of double-counting carbon emitted as CO. The table below shows the fuel carbon
and energy content assumptions used in EDB, as well as the carbon dioxide emissions (assuming
complete combustion) per unit fuel energy.
CARBON AND ENERGY CONTENT ASSUMPTIONS, AND CO2 EMISSIONS PER UNIT ENERGY91.
FUEL
CARBON CONTENT
ENERGY CONTENT
kg CO2/GJ
NATURAL GAS
GASOLINE
KEROSENE/JETFUEL
DIESEL/GAS OIL
RESIDUAL/FUELOIL
LPG/BOTTLED GAS
CRUDE OIL
COAL BITUMINOUS
COAL LIGNITE
FIREWOOD
ETHANOLa
0.51 kg/m3
84.6 % by wt
85 % by wt
86.5 % by wt
84.4 % by wt
82 % by wt
83.5 % by wt
74.6 % by wt
31 % by wt
43.8 % by wt
52.2 % by wt
0.03545 GJ/m3
43.96 GJ/tonne
43.2 GJ/tonne
42.5 GJ/tonne
41.5 GJ/tonne
45.54 GJ/tonne
41.87 GJ/tonne
29.31 GJ/tonne
11.3 GJ/tonne
16 GJ/tonne
0.0219 GJ/l
52.8
70.6
72.1
74.6
74.6
66.0
73.1
93.3
100.6
100.4
110.8
a Ethanol and Methanol carbon contents converted to CO2/GJ using densities of 0.789 and 0.796 kg/l, respectively
b This table shows only gross CO2 emissions from fuel consumption, and does not include CO2 impacts from fuel
production (for example, CO2 produced when hydrogen is made from coal)
c Based on “net” or “lower” heating values.
Emission factors for devices that use fuels whose compositions vary widely must be interpreted and
used with care. Solid fuels--especially coals and biomass fuels--have the most variable composition; the
moisture content, ash content, and heating value (the energy released when the fuel is combusted) can vary
widely from place to place and sample to sample. These differences often effect how relatively "clean" or
"dirty" a particular fuel is. A familiar example is the smoky fire (implying high emissions of particulate
matter) that results when wet wood is burned, while drier wood burns more cleanly. Wood that is high in
90 Major sources for carbon contents included Grubb, M., 1989; "On Coefficients for Determining Greenhouse Gas Emissions
from Fossil Fuel Production and Consumption", P. 537 in Energy Technologies for Reducing Emissions of Greenhouse Gases.
Proceedings of an Experts' Seminar, Volume 1, OECD, Paris, 1989, and ORNL, 1989; Estimates of CO2 Emissions from Fossil
Fuel Burning and Cement Manufacture..., G. Marland et al of Oak Ridge National Laboratory, May 1989, ORNL/CDIAC-25.
91 This is possible because petroleum is 80-85 percent carbon and most (32/44) of the mass of CO comes from oxygen, which
2
is principally derived from the air in which the fuel is combusted, and not from the fuel itself. Note that the CO2 coefficients
as derived here are slightly different (usually no more than a percent) than the factors presented in the IPCC Greenhouse Gas
Inventory Workbook (IPCC/OECD 1993). This variation is well within the variation of fuel carbon contents.
80
A Guide to Environmental Analysis For Energy Planners
pitch (a softwood such as pine, for example) may burn hotter, increasing emissions of NOx. Emission
factors in the literature (or in EDB) may need to be modified if practices for drying or otherwise treating
wood or other fuels differ substantially from those used when the emission factor was measured. It is
necessary, therefore, to consider whether the fuels under consideration are in important respects "cleaner"
or "dirtier than the fuels for which emission factors are described in the general literature (including EDB).
Some characteristics that cause fuels to be described as "clean" or "dirty" are presented in Box 4.6.
Environmental Loading Data: Sources, Estimation, and Uncertainty
81
Box 4.6: "Dirty" vs. "Clean" Fuels
Natural gas is often touted as a clean fuel because very little or no smoke (particulate matter) is
produced when it burns. It also produces less carbon dioxide per unit fuel energy. Even within types of
fossil fuels there are differences. The petroleum product residual oil, for example, is much higher in
sulfur and ash--yielding higher emissions of particulates and sulfur oxides when it burns--than the more
refined products diesel fuel, kerosene, and gasoline (or petrol). Even among gasolines, which are
complex blends of many different hydrocarbon species, there are cleaner and dirtier grades. It is fairly
well known how the composition of gasoline can affect performance of an engine (and thus its
emissions), witness the availability of "super" or "premium" grades. In the United States and other
countries, there are also gasolines that are made cleaner by limiting or prohibiting the use of lead as an
additive. In addition, special gasoline formulations have been developed that reduce the evaporation of
fuel from the fuel system of automobiles, and thus reduce some of the urban air pollution problems
associated with evaporative hydrocarbon emissions.
From a greenhouse gas standpoint, biomass-derived fuels, as a class, are often considered
"clean" because their combustion--when they are produced sustainably --is not accompanied by a net
release of carbon dioxide. When other emissions are considered, however, biomass fuels do not
always fare well in comparison with other alternatives. For indoor air quality fossil fuels are generally
preferred over biomass fuels (for example, use of electric or kerosene cook stoves instead of biomassfueled units). Among the biomass fuels, charcoal typically burns much more cleanly--with less production
of particulate matter and carbon monoxide--than do wood, crop residues, or animal dung. The
production of charcoal, however, has associated environmental impacts at the kiln site, and also requires
more wood input per unit fuel output, thus affecting more land, than other fuels92. The figure below
(after Smith, 1987) shows schematically the relationships between fuel use by type of emission, comfort,
and household income.
Dung
Crop Residues
Minimum
Basic Need
Wood
Kerosene
Emissions
Comfort
Gas
Electricity
Non-Commercial Fuels
Commercial Fuels
Time, Income, Cost
92The emissions and other impacts of charcoal production, for example, are concentrated at the site of charcoal production, and
thus have little impact on the indoor and local air quality in the places where cooking fuels are used. From a national or
regional point of view, however, these impacts can be quite important.
82
A Guide to Environmental Analysis For Energy Planners
Box 4.6: "Dirty" vs. "Clean" Fuels (cont.)
Biomass-based fuels, particularly methanol (CH3OH) and ethanol (C2H5OH), have generated
considerable interest and substantial activity over the last two decades as motor-fuel substitutes for
gasoline. Methanol and ethanol generally burn more cleanly--produce generally lower emissions per
unit energy--than gasoline, but most existing internal combustion engines must be modified in some way
in order to accept these fuels if they are used alone. Another approach has been to blend alcohol fuels,
usually ethanol, with gasoline to create "Gasohol" a fuel that can be consumed in most existing engines.
Some gasohol blends, however, can promote the evaporation of hydrocarbons from the fuel tank, so it is
not possible to state that use of these fuels will lead to lower emissions in all cases.
The composition of coals vary widely depending on their rank (which describes their fuel value
and geological origin), where they are found and how they are treated prior to combustion (if at all).
Different coals have a wide range of sulfur, ash, moisture, and energy contents. Anthracite coals, for
example, though relatively rare, typically are low in sulfur and burn hot and clean. Bituminous coals, the
most common type used in industrial boilers, for electricity generation, and in household applications (in
some countries) vary across a wide range of compositions. Lignite, or "brown" coal, as is found in, for
example the region formerly known as East Germany and in Poland, is typically high in ash and
moisture, and has a relatively low energy content. Brown coal often burns inefficiently and with
relatively high particulate emissions. In many countries, coals are "cleaned"--often by pulverizing them
to a powdered form and washing to remove ash and sulfur--before they are burned. This process
promotes better combustion, but the reduction in air emissions that may result is likely to be
counterbalanced by an increase in solid wastes, such as sulfur-containing sludge, that must be disposed
of. This type of trade-off points up the need to examine the entire fuel cycle, to the extent possible,
when evaluating the environmental impacts of energy alternatives.
Hydrogen is often touted as the ultimate "clean fuel", because its sole direct combustion product
is water vapor, which is rarely considered a pollutant. However, hydrogen combustion in air can emit
nitrogen oxides as molecular nitrogen (N2) from the air combines with oxygen in the flame. Apart from
the difficulties in handling and storing hydrogen gas, many of which are being overcome as technologies
improve, it is important to consider the "upstream" impacts of hydrogen use. Hydrogen can be produced
by a variety of different methods and from a variety of different feedstocks. If hydrogen is produced
from coal, the impacts from the production phase of the fuel cycle may counterbalance the benefits of
having a clean-burning end-use fuel. If, on the other hand, hydrogen is made by electrolysis93 using
electricity from (for example) photovoltaic panels, then the sum of impacts over the entire fuel cycle may
be minimal.
4.5.3 Emission Factors and Fuel Combustion Conditions
Emissions of some types of compounds (typically atmospheric emissions) are particularly sensitive
to the conditions under which fuel combustion takes place. Examples include the relationships between
NOx emissions and combustion temperature, and between CO and hydrocarbon emissions and the ratio of
oxygen to fuel that is present. For certain classes of devices, emissions are modeled as functions of, for
example, the ratio of air entering the combustion area to fuel input, the temperature of combustion, and the
amount of moisture in the fuel. These types of calculations can estimate emissions where monitoring is not
possible or is too expensive, or to estimate the emissions from new conceptual or prototype devices (such
as new car engines) before the devices have been built. These techniques are typically used by mechanical
and chemical engineers, and are also used in more sophisticated emissions modeling frameworks such as
93The electrochemical process of splitting water (H O) into molecular hydrogen and oxygen by applying an electric current
2
across two electrodes that are immersed in a container of water.
Environmental Loading Data: Sources, Estimation, and Uncertainty
83
the European CORINAIR project to track acid gases and other air pollutants (Corinair, 1992), and the
“MOBILE” series of motor vehicle emission models used in the United States.
The fact that emission factors can vary with fuel combustion conditions means that when you use
emission factors you must be aware of and note the conditions under which they were measured and are
applicable, and make sure that your use of them is consistent with the way in which they should be applied.
You may, in some circumstances, need to use more sophisticated modeling approaches to estimate emission
factors that correspond more directly with the technologies in your country than the generic factors that are
available in EDB.
4.5.4 On-Site Impact Coefficients Based on Statistical Analyses
Some of the types of on-site impacts of energy technologies are not measured per se, but are
estimated based on available statistics. In EDB, and in compendia such as the World Health Organization
guide (WHO, 1989), factors that relate quantities such as injuries, deaths, worker-days lost, and accidents
to the amount of energy or fuel produced or consumed by an energy technology are available. Examples of
these factors are deaths from underground coal mining per tonne of coal, injuries per barrel of oil recovered
during oil drilling, or accidents resulting from felling trees for firewood. Since these quantities typically
occur at too low a rate to be measured by an on-site observer, they are estimated based on aggregate
industry statistics. An estimate of coal mining deaths per unit coal mined, for example, might be
calculated by summing all of the reported deaths from the types of coal mines being considered (the
impacts of surface and underground mining would be treated separately) that occur in a country or region
over a period of time--often many years--then dividing by the amount of coal produced by those mines over
that time span. Similarly, to estimate the probability of a sea-going tanker accident resulting (directly or
indirectly) from oil use, you would sum the reported tanker accidents over the last decade, and divide them
by the tonnes of oil transported by sea over the same time period. The accident statistics needed for this
type of analysis are often available from international sources such as the United Nations or the World
Health Organization, from national departments or ministries of labor or commerce94, from labor unions,
or directly from firms in the specific industries. These statistics should be used carefully, as they typically
only represent reported accidents and events. If under-reporting is significant, the impact factors derived
will underestimate the ultimate impacts of the energy technology.
4.5.5
4.6 Determining the appropriate emission factors to use
The major challenge for the energy analyst is to pick the appropriate emission factors from the
many (or few) available options for a given energy technology. Quite often, as in EDB, the variety of
different "sources", or types of equipment, for which emission factors are listed may seem daunting; how do
you, if you are not very familiar with the field, choose the most appropriate option? At the other extreme
specific data may unavailable, with references listing only very aggregate figures. How do you judge if
these are appropriate for your application? In the following subsection we address these questions.
94In the United States, the Occupational Health and Safety Administration (OSHA) is responsible for keeping many of these
statistics.
84
A Guide to Environmental Analysis For Energy Planners
4.6.1 Choosing an Appropriate Set of Emission Factors from the Options Available
Emission factors in the literature--and, as a result, in EDB--are of several types. Some describe
emissions from a general sources, such as "Industrial Sector Coal Combustion", others describe sectoral
emissions from a general source but for a specific area, such as "Industrial Sector Coal Combustion,
Germany". Alternatively, they may describe emissions from a specific device, like "Spreader-Stoker-type
Industrial Boiler, Bituminous Coal-Fired, Wet Limestone Slurry Scrubber Used for Emissions Control".
You will find all three types of emission factors in EDB, and sometimes there will be many more than one
choice for a sector, subsector, end-use, or device that you wish to model.
If you are looking to model a general source of emissions, such as all oil combustion in the
commercial sector, and lack the data necessary to break oil use in the sector down to the subsectoral or end
use level, you may wish to choose a “generic” emission factor. Generic emission factors are designed to be
broadly, if roughly, applicable to a variety of situations, or to act as first-cut estimates until more specific
emission factor estimates can be found. If the factors that you are considering are for a generic
international sector, you need to consider what assumptions underlie the factors. Are the estimates based
on international statistics, and if so, from what countries were data included? Alternatively, were the
estimates chosen as subjectively-representative by those compiling the emission factor database or
compendium? The answers to these questions may affect your decision to use a set of generic international
factors.
Emissions coefficients defined for a single country or region are also available. Before using this
type of estimate, one should consider if the energy device/process in the area under study is similar to those
used in the area for which the estimate is available. If detailed information on energy use is available, and
even at times when it is not, the best approach is often to choose from among emission factors specific to
particular devices. For example, if coal-fired boilers in your country are typically of the spreader-stoker
type, an emissions "source" using that technology would be appropriate for coal combustion in industrial
boilers. Even if you are unfamiliar with a particular technology, you can ask a colleague, or call engineers
at industrial plants to ask what their experience has been.
The goals of a study partially determine the level of effort devoted to the selection of emission
factors. If, for example, the primary goal is to estimate carbon dioxide emissions from coal use, and
investigation of EDB and other databases shows that there is relatively little difference between the
emission factor sets for other emissions, such as ash, associated with the technologies in question, then the
choice of one particular ash emission estimate over another is not critical and the choice can be made
quickly. For a pollutant central to the objectives of a study, or for one whose emissions per unit fuel input
vary substantially from estimate to estimate it may be necessary to spend more effort on determining the
range of values and picking the source that seems most appropriate.
4.6.2 Using Available Sets of Emission Factors to Provide a "First-Cut" Estimate
Sometimes available data on emission factors is inadequate. In such cases, one option is to
determine the most closely-related emissions estimate from the available databases and either to use this
unmodified, or modify it to better suit your application, noting your assumptions under either circumstance.
The basic approach is to use common sense, augmented with a knowledge of the relevant energy-use
technologies. If, for example, you need an estimate for the emissions of a commercial furnace that burns
coconut shells and no coconut shell fueled devices are listed in the available references, you might use
estimates for a similar furnace burning a different type of biomass fuel, say field crop residue or wood, as a
Environmental Loading Data: Sources, Estimation, and Uncertainty
85
proxy until more specific information becomes available. Similarly, a set of emission factors for a
kerosene stove might be a good stand-in to apply to kerosene heaters. What you are looking for first are
similar fuel types: gas, solid, or liquid, biomass or non-biomass. Then try to select the best option from
among the devices available.
A different type of problem arises when equipment burns the same fuels as equipment described in
EDB or elsewhere, but is substantially different, due to age, maintenance (or lack of same) or design.
Automobiles are a good example. In many countries in Latin America, as around the world, vehicles are
equipped with fewer emission controls, and generally are not as well maintained, as in Europe or the United
States. Assuming that (as in EDB) much of the emission factor information in this sector is based on
vehicle stocks in industrialized countries, it might be appropriate, for the purposes of estimating emissions,
to model the average 10-year-old vehicle as being equivalent to an average 20-year-old car, truck or bus in
the U.S.
Finally, there may be cases where emission factors for an energy technology simply do not exist in
EDB or elsewhere. In some cases, however, the technology--perhaps a technology that is relatively new or
untried--is similar enough to an existing technology to allow one to reasonably assume that the
environmental emissions or impacts of the two technologies should be similar. Examples are facilities for
production of fuel ethanol or methanol. Since there have been centuries of experience with fermenting and
distilling ethanol products from biomass feedstocks (e.g. the liquor industry) and with making methanol for
use as a solvent and chemical feedstock, it would not be unreasonable to assume that many of the same
technologies, with their associated emissions and impacts, would be used in making fuel alcohols. This
assumption provides a starting point for estimating the emission/impact factors associated with the new
industries. In these types of comparisons it is important to make sure that you are (when possible)
comparing technologies of similar scales, and that you are comparing effects on a per unit basis. A 10
thousand tonne per year ethanol distillery, for example, may not have the same emissions or impacts per
tonne of product as a one million tonne per year fuel ethanol plant, and it would be inappropriate to directly
compare a reactor used in a methanol plant to a petrochemical plant three times as large.
4.6.3 Combining Emission Factors from Different Sources, and Modifying Existing Emission Factors
Sometimes emission factor estimates from more than one source differ from each other, and yet
appear equally valid for the situation being studied. After examining the derivation of each estimate
carefully and reviewing, to the extent possible, the reasons they differ, it may be reasonable to take an
average over the data sets. Alternatively, you may need data on several types of emissions from a single
source but find that only a few emission factors are available. In this case one approach is to use the
emission factors from several different source categories, perhaps averaging where more than one factor
exists for an emission, in order to develop a composite source. A composite factor set will, of course, be
only approximate, and should be replaced by more source-specific measurements whenever possible.
Combining sets of emission factors into a composite value may also be appropriate when several
different types of processes occur within a single subsector, but sufficiently detailed energy data to
disaggregate the activities is not available. If, for example, you estimate that 20 percent of the autos in a
country correspond to one emission factor and 80 percent correspond to another, but you only have total
gasoline consumption figures and don't wish to, or can't, separate consumption by auto type, then a single
estimated emission factor set can be created by calculating a weighted average. In instances where
emission factors for the same pollutant exist in both sets of factors, multiply the first set by 0.2, and the
second set by 0.8.
86
A Guide to Environmental Analysis For Energy Planners
You may also encounter cases where the equipment is slightly different than that for which you
have emission factors, but where simple adjustments can be made to reflect those differences. Accounting
for the efficiencies of different types of emission control systems is one example. Many of the coefficients
in EDB describe pollutant emissions for equipment without emission controls. If, for example, industrial
coal-fired boilers in your country are required to use electrostatic precipitators or similar technologies to
remove particulate matter from the exhaust gas stream, then an emission factor for the boiler can be
estimated by taking the base (uncontrolled) emission factor for particulate matter and multiplying it by 0.01
(assuming that the electrostatic precipitator collects 99 percent of the particulates). In some cases emission
control equipment affects emissions of more than one pollutant, though often not in the same proportions.
Typically, not all pollutants will be reduced by a single control technology, and some emissions may even
increase slightly as others decline.
4.6.4 Limits and Pitfalls of these Approaches to Emission Factor Estimation
The above methods are designed only to provide approximate values that serve until more
information is available. You can reduce possible errors in assignment or modification of emission factors
by learning as much as possible about the energy system for which you wish to estimate emissions and the
derivation of the available emission estimates. While an obvious possible error associated with the
approaches listed above is to assign emission factors that are much too high or low, a less obvious but
potentially more serious problem is that by creating placeholder values and inserting them into the
calculations you may be institutionalizing them. That is, the next analyst who uses your numbers may
assume that they are based on better data than is actually the case, and will use them without properly
reviewing new information or data sources. It is therefore critical to clearly document all of the
assumptions that you make in assigning, modifying, and using emission factors, carefully noting where
guesses or approximations have been made and where more research is necessary. Even if you have to
make many assumptions to derive an initial emission factor data set, however, the effort is worthwhile,
because you are 1) providing a starting point that future energy/environment analysts can build on, and 2)
you are contributing to the process of developing well informed energy and environmental policies.
Environmental Loading Data: Sources, Estimation, and Uncertainty
87
4.7 Uncertainty, Errors and Limits of Applicability
The uncertainties associated with the emission factors listed in EDB and elsewhere vary greatly
among pollutants. Estimates of fossil fuel CO2 emission factors are primarily dependent on fuel carbon
content, and thus usually have relatively little variability, particularly for petroleum products and natural
gas. Carbon dioxide emission factors can probably be considered accurate to within approximately 5 to 10
percent, as the carbon contents of fuels, particularly fossil fuels, do not vary widely. Other emission
factors are often based on the results of a relatively small number of tests of fuel use in particular types of
equipment. In order to ascribe emission factors to specific sectors or subsectors of the energy economy it is
necessary, as noted above, to make a number of judicious assumptions. As a result, it is difficult to assign
an uncertainty to all estimates of emission factors, as the accuracy of the factor will vary with how and for
what the emission factors, which are estimates themselves, are applied. Increased emissions testing in both
the developing and industrialized world, with centralized international reporting of results, could help
greatly in reducing these uncertainties and in expanding the range of emission factors available as well as
their accuracy, as discussed below.
Until a large range of accurate emission factors is available, one measure that you, the analyst, can
take to evaluate the effects of uncertainty in emission factors on your emission estimates is to use the range
of available emission factors--for example, high and low values for a particular pollutant and energy
technology--to calculate high- and low-case pollutant loadings. The way that you would carry out this sort
of sensitivity analysis using LEAP and EDB is to “link” different EDB sources, with high and low-case
emission factors, to your LEAP Demand devices and Transformation processes.
4.7.1 Validity of Emission Factors based on Empirical Tests
The validity of the emission factors you find in the literature, and of those you measure yourself, is
a function of the way in which the empirical data used to estimate the factors were collected. Some of the
agencies that estimate emission factors, including the U.S. Environmental Protection Agency (USEPA), use
a system to rate the "reliability" of emission factor estimates. The USEPA's rating system uses the letters
A through E; factors rated "A" are considered the most reliable, while factors rated "E" are probably at best
indicative, and are not to be used for rigorous work. The sampling procedures used, the number of tests
done, and the range of equipment sampled all contribute to the reliability of an emission factor. Table 4.4
provides a sampling of sources of emissions and the emission factor ratings that the USEPA has assigned
to pollutant emissions from these sources. Note that these vary widely across pollutants and sources.
Applying an emission factor based on a limited number of tests or a limited range of samples is the
only course available under some circumstances, but it should be recognized that the emissions estimates
produced with such a factor will be uncertain. You may often find that an emission factor in the literature
is based on tests of only one or a few models of a certain type of device, recognizing this you should use the
estimate with caution, as you probably don't know for sure how well the characteristics of the test devices
match the category of devices for which you are trying to model emissions.
88
A Guide to Environmental Analysis For Energy Planners
Table 4.4:
Sampling of USEPA Emission Factor Ratings for Various Energy Technologies
Source Description
Pulverized Bituminous Coal
Boiler, Dry Bottom
Overfeed Stoker Bituminous
Coal Boiler
Hand-fed Bituminous Coal Boiler
Fluidized Bed Bituminous Coal
Boiler (Bubbling Bed)
Utility Boilers--Residual Oil
Residential/Commercial
Furnaces/Boiler, Distillate Oil
Industrial Boilers--Natural Gas
LPG Combustion (All)
Bagasse-fired Boilers
Residential Fireplaces
Residential Wood Stoves
Natural Gas-Fired Turbines
Large Diesel/Gasoline Engines
USEPA Emission Factor Ratings By Type Of Emission
SOx
NOx
N2O
CO2
CO
Partic. CH4 TOC*
A
A
D
A
A
B
B
B
A
E
B
C
B
B
D
E
E
D
E
E
E
D
E
E
E
E
E
E
A
A
A
A
A
A
A
A
A
A
A
A
B
E
A
E
C
C
C
C
D
A
E
B
E
C
B
B
E
D
C
C
E
A
B
B
D
D
E
A
C
C
B
B
B
B
D
D
E
D
D
E
D
D
* Total Organic Compounds. For some sources, ratings in this column refer to volatile organic
compounds.
Source: USEPA document Compilation of Air Pollutant Emission Factors, Volumes I and II (plus
supplements). USEPA, Washington, D.C., USA. This document is commonly referred to by its report
number: AP-42. Information in the table above is derived from a 1995 updated to AP-42.
4.8 Categories of emission factors particularly sensitive to local conditions
4.8.1 Household stoves
Demand for biomass fuels, typically used in household stoves, can be a significant contributor to
problems of land degradation, soil erosion, and ecosystem damage. In addition the extensive use of
traditional cooking fuels and equipment, may pose considerable health risks, particularly to women. For
example, very high concentrations of carbon monoxide (940 ppm) have been reported for households in
Lagos, Nigeria. (Smith et al, 1983, as reported in Adegbulugbe, 1992). Emission factors for biomass
stoves are especially sensitive to local conditions for several reasons. First, biomass fuel characteristics
vary from country to country, region to region, house to house, as well as temporally from season to season
and even day to day. What is burned may depend on what is foraged--wet wood one day, dry wood the
next, bark, crop wastes, or manures at other times, and possibly even charcoal or coal. Each fuel has its
own specific characteristics (density, levels of ash and moisture, size) and composition, leading to different
combustion characteristics and different levels of emissions of specific pollutants. Second, there are a
wide variety of wood stove designs, from the simple three-rock stoves to the newer fuel-efficient models.
Stoves are typically built with local materials, which further increases the variability of their performance.
People in different countries operate stoves in different ways, depending on cooking customs, local cuisine
(some foods must be heated rapidly, while other foods demand a steady but low source of heat over a
number of hours) and on secondary uses of the stove, such as space heating and insect control (by smoke)
in the thatched roofs of cottages. Even differences in fire and stove management from household to
Environmental Loading Data: Sources, Estimation, and Uncertainty
89
household, or within the same household over time can be significant. Each source of variability
contributes to make "standard" emission factors difficult to determine. Given the importance of emissions
from household stoves in contributing to both indoor and local air pollution, this sector is a good candidate
for an active international research and an emissions testing program.
Table 4.5:
SAMPLING OF EMISSION FACTORS FOR HOUSEHOLD STOVES
Type
WOOD
Default
Manila
Manila (5% C in ash/TSP)
Generic wood stove
Generic tropical wood stove
Chula 1
Chula 2
3 stone fire
Metallic stove
Tara ("improved stove")
CPS ("improved stove")
CPRI ("improved stove")
CHARCOAL
Default
"Haiti"
Manila
LPG
Default
Manila
All-purpose, generic, uncontrolled
KEROSENE
Default
Manila
Kerosette-type stove
Nutan
Generic furnace
Radiant stove
Convective stove
Multistage stove
OTHER BIOMASS
Coconut husk stove
Dung
COAL
Generic DC coal stoves
Handfired bituminous
Handfired anthracite
Mafalfa
Maxaquene
Indian stove
NATURAL GAS
Generic cooking
Region
Source
Unit
CO2
CO
CH4
HC
Senegal
Phil.
Phil.
------------India
India
Best guess
Smith 1992
Smith 1992
Ellegard 1989
Smith 1987
Smith 1987
Smith 1987
Smith 1987
Smith 1987
Smith 1987
Smith 1987
Smith 1987
g/kg
g/kg
g/kg
g/kg
g/kg
g/kg
g/kg
g/kg
g/kg
g/kg
g/kg
g/kg
1420
1620
1560
1400
1460
1460
1480
1460
1560
1540
1490
1420
100.0
100.0
99.0
121.0
80.0
72-92
66-76
39-106
13-22
23-37
48-67
86-113
9.0
9.0
8.0
Senegal
Haiti
Phil.
Best guess
Ellegard 1989
Smith 1992
g/kg
g/kg
g/kg
2760
2780
2740
247.0
264.0
230.0
8.0
4.0
8.0
4.0
Senegal
Phil.
-------
Best guess
Smith 1992
USEPA 1985
g/kg
g/kg
g/kg
2950
3110
2980
24.0
24.0
0.4
0.0
0.0
0.1
3.0
3.0
0.2
2.0
0.0
0.06
2.0
0.0
0.06
Senegal
Phil.
Best guess
Smith 1987
Smith 1987
Smith 1987
WHO 1982
Smith 1987
Smith 1987
Smith 1987
g/kg
g/kg
g/kg
g/kg
g/kg
g/kg
g/kg
g/kg
3010
3030
2980
3030
3090
3090
3090
3090
50.0
38.0
67.0
41.0
0.3
4.5
0.0
0.1
1.0
1.0
11.0
11.0
0.6
17.0
4.00
17.0
5.00
2.80
3.00
0.02
0.02
Smith 1987
g/kg
1220
110.0
USEPA 1989
Ellegard 1989
Ellegard 1989
Ellegard 1989
Ellegard 1989
Smith 1987
g/kg
g/kg
g/kg
g/kg
g/kg
g/kg
2550
2630
2830
2580
2530
2520
1050.0
48.5
138.0
80.0
112.0
120.0
g/cubic meter1850
9.8
7.5
13.0
12.0
3.9
7.5
0.4
NOx
SOx(a)
TSP
0.8
0.5
10.00
0.8
0.7
0.4
0.6
11.40
9.00
4.2-9.9
8.7-9.1
2.9-15
1.3-2.6
1.1-2.5
1.8-3.8
0.3-8.3
0.7
0.7
2.40
2.40
N20
0.06
0.06
0.06
0.06
0.06
2.3
0.6
0.1
0.1
0.03
0.03
0.05
0.05
35.00
0.0
4.0
15.8
5.8
5.9
1.1
10.0
5.2
2.9
0.9
6.0
3.4
2.0
0.2
0.4
14.6
13.3
12.2
7.2
10.0
10.80
0.70
2.00
6.30
1.20
0.02
Blank entries indicate no data are reported for that pollutant.
(a) SOx emissions will depend on S content of local fuel used.
A sampling of a number of emission measurements for household biomass and fossil-fueled stoves
are given in Table 4.5. These measurements have primarily been made for small Asian stoves, but include
the results of recent tests of small household stoves that indicate emissions of previously unmeasured
greenhouse gases (CH4, N20, etc.) could be very high (Smith et al., 1992) have also been incorporated.
Combining these estimates with other emission estimates for "generic stoves", we have forwarded our
current "best guess" or “default” estimates for these devices, which are also shown in the table below.
90
A Guide to Environmental Analysis For Energy Planners
4.8.2 Vehicles
Transport sector emissions are a major source of urban air pollution. In Asian, Latin American,
and OECD cities, motor vehicles generally account for about 90% of CO emissions, and often a large
majority of HC and NOx emissions. (Faiz, 1991) While not yet approaching the problems found in major
cities in Asia and Latin America, urban air quality problems related to transport emissions (vs.
household/industrial emissions) are also of increasing concern in many African cities. For example, high
levels of CO and SO2 have been measured in Ibadan City, Nigeria, and typical haze and eye irritation are
indicative of high levels of photochemical smog on major transportation routes in Lagos (Adegbulugbe,
1992). In addition, leaded gasolines pose health risks, particularly to small children who breathe the air
with higher lead concentrations found at or near tailpipe heights. These health concerns are shared in most
urban areas of the world, with Manila, Bangkok, and Mexico City being notable examples.
Transport sector emissions depend on a variety of factors: vehicle type and emission controls, fuel
characteristics, maintenance level, fleet age, and driving conditions. It is thus very important to take these
factors into account in deriving and applying emission coefficients. Many published transport sector
emission coefficients implicitly assume vehicle stock and characteristics similar to those found in
industrialized regions. While these conditions are obviously not found in most developing countries, local
data are generally unavailable. Furthermore, the data are often U.S.-based, reflecting substantially
different vehicle stock and emission control regulations than found in many other regions.
Some of the available data on vehicle emissions are shown in Table 4.6, below. These data
illustrate the wide range of emission factors pertaining to different models and vintages of vehicles. The
table illustrates the dramatic reductions in emissions of several pollutants (CO, HC, and TSP) achieved in
newer U.S. vehicles, due to emission reduction technologies (e.g. catalytic converters) resulting from U.S.
regulations.
4.8.3 Fuel extraction activities
Another area where emission and impact factors may be extremely site specific is in energy
extraction, specifically mining of coal, oil shales, and uranium ore, and drilling for petroleum products and
natural gas. In coal mining, the principal emission to the atmosphere is methane. The amount of methane
released per tonne of coal mined varies widely from coal seam to coal seam, depending on geology and
whether the coal is surface-mined95 or underground mined. Within the latter category, methane emissions
vary according to mining procedures (USEPA, 1990a) such as how much coal is left in place and what type
of ventilation is used. Other emissions from coal mines, such as acid mine drainage, also depend largely
on mining practices and site-specific geology, topography and hydrology. For oil and gas drilling large
variations in emissions are likely to arise due to differences in the state and maintenance of equipment , the
degree to which natural gas is captured and routed to pipelines instead of being vented or flared, and the
general care and vigilance with which the operation is run.
95Surface-mined coal is removed by first scraping off the rock and soil (called the "overburden) that lies above the geological
strata where the coal occurs (called the "coal seam"). Once the overburden, typically several to tens of meters thick, is
removed, the coal itself is scraped away, usually with the aid of very large heavy equipment. Underground mining, while also
usually machine aided, involves digging a shaft into the earth to the coal seam removing the coal, and bringing the mined coal
back up to the surface through the shaft.
Environmental Loading Data: Sources, Estimation, and Uncertainty
91
Table 4.6:
SAMPLING OF EMISSION FACTORS FOR MOTOR VEHICLES
Type
Source
AUTOMOBILES
Gasoline
Senegal - Mix of India and Netherlands, IPPC/uncontrolled
Car-India
Bose et al. 1992
Jeep-India
Bose et al. 1992
Car - U.S. - uncontrolled
IPCC 1991
Car - U.S. - 3 way watalyst
IPCC 1991
Car-Netherlands: 1985 fleet, 1.4-2 l engine
EEC 1988
U.S. midsize, 27 mpg, uncontrolled
OECD 1986
1965 U.S. em. std., emissions in 90, leaded
USEPA 1985
USEPA 1985
1975 U.S. em. std., emissions in 90, unleaded
1985 U.S. em. std., emissions in 90, unleaded
USEPA 1985
1990 U.S. em. std., emissions in 90, unleaded
USEPA 1985
Diesel
Senegal - Mix of India and Netherlands, IPPC/uncontrolled
Jeep - diesel
Bose et al. 1992
Car - U.S. - advanced control
IPCC 1991
Car - U.S. - uncontrolled
IPCC 1991
Car-Netherlands: 1985 fleet, 1.4-2 l engine
EEC 1988
MOTORCYCLE/OTHER
Gasoline
2 wheeler - India
Bose et al. 1992
Motorcycle - U.S. - uncontrolled
IPCC 1991
BUSES
Diesel
India
Bose et al. 1992
LIGHT DUTY VEHICLES (LDV)
Gasoline
LDV - U.S. - uncontrolled
IPCC 1991
LDV - U.S. - advanced 3 way catalyst
IPCC 1991
TRUCKS/HEAVY DUTY VEHICLES (HDV)
Diesel
HDV - U.S. - uncontrolled
IPCC 1991
HDV - U.S. - advanced control
IPCC 1991
BOATS
Gasoline
Outboard engine
USEPA 1985
Diesel
Best guess
Boats
IPCC, 1991
Commercial Steamships
EPA, 1985
Unit CO2 CO
g/kg
g/kg (a)
g/kg (a)
g/kg
g/kg
g/kg (b)
g/kg
g/kg
g/kg
g/kg
g/kg
2660
HC CH4
38.5
53
54
50.3
10.5
24
30
75
33
12
7
1.38
2470
2160
2680
2920
3050
263
354
367
323
50
171
380
582
251
97
13
g/kg
3140
g/kg (a)
g/kg
3188
g/kg
3188
g/kg (b)
12
3
11
6
22
8
1
3.6
3.1
15
0.06
g/kg (a)
g/kg
3172
g/kg (a)
519
324
405 111.0
22
8
1.38
0.32
0.12
0.06
5.60
NOx SOx TSP
32.4
23.1
24.0
17.0
7.9
41.7
48.5
169.0
13.5
8.3
4.6
0.39
0.78
0.78
11
5.1
8.0
6.1
15.9
7.13
7.13
n/a
3.2
0.82
40.9
7.13
Pb
0.50 0.243
0.243
0.243
N20
0.04
0.04
0.30
1.24
1.01
0.32
0.96
0.16
0.27
0.30
0.027
0.004
0.004
0.004
4.98
0.17
0.08
0.08
0.08
9.78
0.254
0.04
0.17
g/kg
g/kg
3172
3172
303
58
58.1
9.4
1.18
0.50
17.9
8.4
0.04
0.30
g/kg
g/kg
3188
3188
22
22
7.6
4.1
0.26
0.19
42.9
16.3
0.08
0.08
g/kg
2240
534
178
g/kg
g/kg
3120
3188
3140
11
21
1
2.7
4.9
0.4
0.23
0.23
1.1
1.04
35
67.5
3.3
7.82
2.07
7.82
2.07
0.08
0.08
Blank entries indicate no data are reported for that pollutant.
(a) Converted from g/l using a density of .74 kg/l for gasoline and .87kg/l for diesel.
(b) Converted from g/km, assuming 25 mpg or 9.4l/100 km.
The health and safety impacts of both mining and petroleum/natural gas extraction also vary
widely with the particular operation. Underground coal mines tend to have more accidents and injuries per
tonne of coal extracted than do surface mines, but among underground mines, the number and severity of
incidents varies according to the types and quality of equipment used, safety regulations and protocols, the
particular mining methods employed, and the geological nature of the coal and surrounding bedrock.
Injuries and accidents in oil and gas fields are also, primarily, a function of equipment maintenance and the
degree to which good safety practices are followed.
92
A Guide to Environmental Analysis For Energy Planners
4.9 Major sources and types of emission factors data
EDB includes emission factors from more than 50 different documents and databases. Full
citations for these sources are given in the References section of EDB (an annotated version of this
reference list is provided as Annex 2 to this document), and many of them have been used in preparing this
manual. There are several major, general sources of emission factors. These are the emission factors
collected by the U.S. Environmental Protection Agency (USEPA), the Intergovernmental Panel on Climate
Change (IPCC), the CORINAIR database assembled by researchers in Europe, and the World Health
Organization’s Rapid Assessment of Sources of Air, Water, and Land Pollution (WHO, 1982).
4.9.1 The USEPA's Emission Factor Databases
The USEPA maintains a database of emission factors, as well as active research programs in (to
name a few) measuring emissions from different types of devices, estimating emissions of different
compounds from different sources, and refining methods for testing emissions.
The best-known set of documents on emission factors published by the USEPA are referred to as
the "AP-42" series, titled Compilation of Air Pollutant Emission Factors. Volume I of this series covers
"stationary" sources of air pollution--from utility boilers to home wood stoves. Volume II covers mobile
sources--from motorcycles to ships to heavy equipment. AP-42 covers what are known as the "criteria"
air pollutants, principally CO, NOx,, SOx, hydrocarbons, and particulates. Emissions of lead are
occasionally included as well, as are emissions of methane, nitrous oxide, and carbon dioxide. AP-42 was
originally published in the early 1970's, and different parts of it have been updated many times, including
an update to some sections in early 1995. Many of the stationary-source emission factors in AP-42 are
also contained in a database called EFACTOR which is referenced by process type (e.g. "industrial coal
boilers") and by Source Classification Code. In addition to emissions from fuel consumption, both AP-42
and EFACTOR contain factors describing emissions from other processes, including those in the industrial
and agricultural sectors.
Other tools available from the USEPA include a databases of VOC (volatile organic carbon)
profiles, which give the estimated breakdown of total VOC emissions among specific species of organic
molecules (e.g. methane, ethane, benzene, etc.) for emissions from many sources, and a database of PM
(particulate matter) profiles, breaking down emissions of particulate matter into several size ranges96. All
of these databases are available from the EPA on a CD-ROM disk (a format similar to the "compact disks"
used for sound recording, but containing data instead of music) called "AIR CHIEF" (USEPA, 1992).
These databases and other materials are also available through the USEPA's "CHIEF" electronic bulletin
board system. Researchers whose computers are equipped with modems can call up this bulletin board
and obtain a wide variety of information on environmental topics, as well as the most recent updates of
emission-related EPA documents, computer models, and databases.
The EPA also is very active in the field of global warming, and has published a compendium of
factors to be used in the estimation of greenhouse gas emissions (USEPA 1990b). This compendium
draws heavily on emission factors from AP-42.
96Particulate matter emissions of different sizes cause different human health impacts. For instance, while particulates of
larger than a certain size are filtered out in our noses and throats, smaller particles can make their way to our lungs, where they
can cause or exacerbate respiratory problems.
Environmental Loading Data: Sources, Estimation, and Uncertainty
93
4.9.2 Emission factors for Greenhouse Gasses from the IPCC
In February of 1991, the OECD (Organization for Economic Co-operation and Development,
based in Paris) organized an "Experts Meeting" for the IPCC in order to reach consensus on emission
factors and other procedures for data collection and the estimation of greenhouse gas emissions from
anthropogenic (human) activities. As a part of this effort, which is documented in the report Estimation of
Greenhouse Gas Emissions and Sinks, (OECD 1991), a compilation of emission factors for energy-using
equipment was produced, covering the residential, commercial, industrial, and utility sectors, and providing
factors for emissions of CO2, CO, NOx, CH4, N2O, and non-methane VOCs. Emission factors for
agricultural activities and land-use changes are also provided in this report. Much of the information in
this report has been updated and re-formatted in the IPCC/OECD compendium Greenhouse Gas Inventory
Workbook: IPCC Draft Guidelines for National Greenhouse Gas Inventories (IPCC/OECD 1993). For
the energy sector, this set of emission factors draws heavily on the USEPA documents referenced above.
4.9.3 CORINAIR
CORINAIR is a subset of a program called CORINE, which is designed to spur and coordinate the
collection of environmental information among the countries of Europe. The program is under the
auspices of the Commission of European Community (CEC). CORINE stands loosely for "Coordination - Information -- Environment". CORINAIR is the portion of the program dealing with atmospheric
emissions. Part of the CORINAIR project has involved the compilation of an emission factors handbook
covering a range of economic activities, including stationary sources, agricultural sources, road
transportation, and "nature" (biogenic emissions). The emissions included in the emission factor database
are SOx, NOx, and VOCs, although the database may be extended to cover other pollutants (Fontelle et al,
1990). The database is called EEC - DG XI - CORINAIR Emission Factors, and is available from the
CEC (Veldt and Bakkum, 1988). The emission factors in this compendium are drawn from collaborating
researchers and institutions throughout Western Europe, and may include some data from other sources
(such as the USEPA) as well.
4.9.4 The World Health Organization
Another source of information used frequently in compiling EDB has been the World Health
Organization’s Rapid Assessment of Sources of Air, Water, and Land Pollution (WHO, 1982).
This compendium includes some factors for emissions of pollutants to air and water for various energy
sector technologies, but was also used as a source for information on direct health and safety impacts of
energy technologies.
Summary: potential uses and misuses of emission factors
Emission and impact factors are essential when you are preparing an emissions inventory or
projecting energy-related emissions or impacts. Databases such as EDB make it possible to come up with
numerical estimates without an extensive, difficult, and often expensive effort to collect environmental data.
Emissions estimates are produced by applying emission factors to economic or energy data that are usually
more easily obtained than basic environmental data. Emissions estimates can be used as inputs to models
94
A Guide to Environmental Analysis For Energy Planners
that simulate the effects of emissions on parameters such as human health, local air quality, acid
precipitation, or climate change.
Some of the different methods used to sample emissions were discussed earlier in this Section;
some are better than others for particular applications, and some, with the passage of time, may come to be
seen as error-prone. In general, the higher the number of tests performed, or samples taken, to estimate an
emission factor, the higher will be the confidence in the final figure established. Samples should ideally be
taken over a range of operating conditions, and emissions data for a range of different individual
installations or devices should be collected. As an example, if you wanted to derive a set of emission
factors for the fleet of "tricycles" (a small motorcycle equipped with a sidecar for passengers and/or goods-they are in wide use in the Philippines, Thailand, and other Asian nations) in your country, you would
want to take several readings of the emissions for each test vehicle, but also to be sure to test vehicles of
different ages, from different manufacturers, and in different locales, trying to get a mix of vehicles
representative of the country-wide fleet. A similar procedure would be optimal if you were trying to
estimate emissions from wood stoves, which vary greatly in their design and operating characteristics from
place to place and even, sometimes, household to household.
As in all types of numerical estimates, however, it is important to bear in mind the limitations that
exist to using published estimates of emission or impact factors. In particular, it may be useful to ask
yourself the following questions:
•
Does this particular emission (or impact) factor (or set of factors) correspond well to the particular
device, technology, or situation under consideration?
•
What is the underlying uncertainty in the emission factor, and how does it correspond to the uncertainty
in the data (such as energy use data) to which I want to apply it?
•
Do I know enough about the source of emissions I wish to model (such as the types of wood stoves
used, and how they are operated) to make reasonable assignments of emission factors from the
literature? If not, how can I find out more?
•
Did I adequately document my assumptions and sources so that future research can build upon my
work?
•
Are my efforts in finding just the right emission factor for a particular device or set of devices worth
the effort, that is, will the use of factor A versus factor B make a big difference in my final result?
(This helps determine how much work to devote to particular aspects of your study, keeping in mind
the overall goal).
It is important, and perhaps reassuring, to think of your efforts at using emission and impact
factors in energy/environment analysis as steps in an ongoing process that will involve future updates and
improvements. As such it is important to do the best job you can and to realize that part of the job will be
to identify gaps in the data and areas in need of further research. Your efforts and future research will help
to reduce the uncertainties surrounding the relationships between energy choices and the environment, and
ultimately lead to better-informed decisions on energy policy.
5. Developing Loadings Inventories and Projections for the Energy
Sector
Developing Loadings Inventories and Projections for the Energy Sector
95
5.1 Introduction
In previous sections of this manual we have tried to give an overview of the basic approaches in
energy/environment planning, review the major environmental issues that are of concern to planners and
convey a sense of what emission factors are and where they come from. In this section our focus is more
specific. The goal here is to provide a general step-by-step guide to preparing pollutant and impact
loadings inventories and projections. After a brief description of LEAP and EDB, we present the overall
steps that are involved in such an analysis, followed by a concrete example--for a hypothetical “Country
X”--showing how these steps can be implemented. This section ends with a description of a LEAP and
EDB application in Costa Rica.
5.1.1 Why Prepare Pollutant Loadings Inventories?
Inventories of pollutant loadings--and of estimated direct impacts--from energy sector activities
have a number of uses in the fields of planning, policy evaluation, and environmental regulation. An
inventory of pollutants is an estimate of current pollutant loadings and other impacts, presented by type of
pollutant or impact and often by location of emissions and/or by economic sector. Pollutant “loadings” are
releases of gaseous, liquid, or solid wastes to the environment. Some of the specific uses of inventories or
loading are as follows:
•
Estimation of future loadings: Planners use “base year” estimates of pollutant loadings as an input to
projections of future pollutant loadings. These estimates, in turn, serve as indicators of future
environmental quality, or inputs to other models.
•
Estimation of the ambient local concentrations of key air pollutants: Inventories of key air pollutants
(such as NOx, SOx, CO, particulate matter, hydrocarbons) in, for example, an urban airshed are used
to estimate the concentrations of these pollutants--and the chemical species that are formed by
atmospheric processes--in the local air. These concentration estimates, in turn, are used to determine
health risks. Box 5.1 describes an example of such an application in Mexico City. Similar estimates
of the ambient concentrations of toxic air pollutants also start from emissions inventories, as do
estimates of the concentrations of water pollutants in receiving rivers, lakes, and other bodies of water.
•
Estimation of the transport of air and water pollutants: Inventories of pollutants, including toxic and
other air and water pollutants, can be used as inputs to models that estimate the patterns with which
these pollutants are dispersed in the local environment.
•
Input to transport models of regional pollutants: Precursors to acid precipitation, for example (see
Section 2) are emitted locally but may have their major environmental impacts hundreds or thousands
of kilometers away. Estimates of local loadings of these pollutants are used as inputs to the models
that track acid precipitation.
•
Input to global greenhouse gas models and national greenhouse gas abatement studies: Inventories
of greenhouse gas (GHG) emissions can be used as inputs to estimates of emissions of these gases on a
global level. These in turn provide inputs to predictions of future concentrations of GHGs, which are
used to evaluate the environmental consequences of GHG concentrations. Preparation of a GHG
inventory is required of all nations that have signed the Framework convention on Climate Change. It
96
A Guide to Environmental Analysis For Energy Planners
is also the necessary first step in preparing national plans to abate future emissions of greenhouse
gases.
A number of different analysis tools can--and should--be used to perform the types of studies listed
above. LEAP is just one of these tools, but its characteristics--including its ability to link to the
Environmental Database and the way that it can be used to easily model future scenarios--make it
particularly useful in many energy planning activities. LEAP and EDB were used for the “Country X” and
Costa Rica studies described below.
Box 5.1: Using an Emissions Inventory for Mexico City
The capital city of Mexico, Mexico City, is home to over 19 million people. Mexico city lies in a
high-altitude valley surrounded by mountains, two of which are over 5000 meters tall. This topography,
coupled with the light winds in the area, means that air pollutants tend to remain in the area once
emitted. The many and varied activities of the population, including petroleum refining, electricity
generation, numerous industries and service establishments, and a vast fleet of transport vehicles--all
contribute emissions to the airshed, resulting in frequent episodes of poor air quality.
To help understand and alleviate this problem, Mexican authorities have, with assistance from
UNEP and others, established a system of pollution monitoring stations, and have also established an
inventory of air pollutant emissions, as shown in Table 5.1, below. This inventory has helped to indicate
what sectors and processes are major sources of emissions, and has helped local authorities to design
and implement contingency programs to respond to severe pollution episodes, as well as medium-range
plans for halting the growth of pollution. Contingency programs in Mexico City include reducing the
activity of highly polluting industries, restricting vehicle traffic. More permanent changes include closing
the local PEMEX refinery, converting power plants to run on natural gas, lowering the sulfur content of
fuel oil burned locally, retrofitting vehicles to burn natural gas, limiting automobile CO emissions, and
restricting commuter traffic. A longer-term initiative is to replace old, high-emissions industries with nonpolluting activities.
Source: World Health Organization and United Nations Environment Programme (1994), “Air Pollution in
the World’s Megacities”. Environment, Volume 36, #2, pages 25 to 27.
Developing Loadings Inventories and Projections for the Energy Sector
97
Table 5.1:
Emissions Inventory for the Metropolitan Area of Mexico City
Sulfur
Dioxide
Sector
Energy
PEMEX*
Power Plants**
Industry
Industry
Services
Transport
Private Cars
Taxis
Combis and minibuses
Urban buses
Suburban buses
Gasoline trucks
Diesel trucks
Other
Environmental Degradation
Erosion
Forest fires, etc.
TOTAL***
Partic.
Carbon
Oxides of
Non-Methane
Matter
Monoxide
Nitrogen
Hydrocarbons
(Units: Thousand tonnes per year)
14.7
58.2
1.1
3.5
52.6
0.5
3.2
6.6
31.7
0.1
65.7
22.0
10.2
2.4
15.8
0.4
15.8
0.4
39.9
0.1
3.5
0.8
0.8
5.2
13.0
0.9
20.0
0.2
4.4
1.0
1.0
0.2
0.6
1.1
0.9
0.1
1,328.1
301.1
404.4
6.2
12.6
779.5
16.5
5.0
41.9
9.5
10.0
8.0
18.2
16.9
26.1
2.7
141.0
31.9
42.7
2.4
5.3
67.8
7.2
1.6
0.0
0.1
205.7
419.4
4.2
450.6
0.0
27.3
2950.6
0.0
0.9
177.3
0.0
199.7
572.1
*Closed in 1991
**Switched to natural gas in 1991
***Sums of columns may not add to total, due to rounding.
Source: WHO and UNEP, 1994.
5.2 LEAP and EDB
Together, LEAP and the Environmental Database (EDB) comprise a computerized modeling
system designed to explore alternative energy futures, along with their principal environmental impacts,
using the analytical steps outlined below. As a flexible, model-building tool, model relationships and detail
can be tailored to the dynamics of particular energy situations and to the data constraints of individual
applications. A brief description of LEAP is included in Box 5.2, below.
98
A Guide to Environmental Analysis For Energy Planners
Box 5.2: The Structure Of LEAP
LEAP is structured as a family of easy-to-use microcomputer programs, the LEAP energy planning system
is suitable for performing energy assessments in developing or industrialized countries, for multi-country regions, or
for local planning exercises. It consists of three groups of main programs: Energy Scenario, Aggregation, and the
Environment (and an optional add-on group for making macroeconomic projections). The Energy Scenario
programs address the main components of an integrated energy analysis: demand analysis, energy conversion,
and resource assessment. This group consists of three programs for building scenarios (Demand,
Transformation, Biomass/Land Use), a program for reporting environmental emissions and one for comparing
and evaluating scenario costs and impacts. The planner uses the scenario building programs to develop current
energy balances, projections of supply and demand trends, and scenarios representing the effects of energy
policies, plans and actions. The Environmental and Evaluation programs compute the physical impacts of moving
from one scenario to another, the economic costs and benefits, and the environmental emissions. The
Aggregation program assemble area level (district, nation, region) energy accounts and projections into multi-area
results. The Environmental Data Base, EDB, provides a comprehensive summary of the information linking energy
production, conversion and consumption activities to air and water emissions, and other environmental and health
consequences, that can be linked to energy scenarios to provide measures of the environmental consequences of
alternative futures. Note that the diagram below does not include the newest LEAP program element, namely the
fuel chain program, which allows the side-by-side evaluation of the resource, cost, and environmental impacts of
different ways of providing the same energy services.
Energy
Scenarios
A g g regation
E n v ironm e n tal
Database
Demand
T r a n s f o r m atio n
B iom ass
E n v ironm e n t
Evaluation
The Demand program provides a framework for disaggregated, end-use analysis of final energy
requirements. Data are assembled in a hierarchical format, based on four levels: Sectors, Subsectors, End-uses,
and Devices. Depending on data availability and analytical choices, the user can define an appropriate structure
and select from among several options for making future projections (such as growth rates, fixed targets, elasticity
relationships, etc.). The Transformation program simulates the energy sector conversion processes that turn
primary resources, such as hydropower and crude oil, into final fuels, such as electricity and kerosene. The
program compares the primary resources and fuel imports and exports required to provide the final fuel
consumption calculated by the Demand program. Major transformation processes are handled by specialized
modules — e.g., electricity production, ethanol plant, oil refining, oil and gas production, coal mining, charcoal
kilns, biogas production, etc. — while others may be user defined. The Biomass Resource/Land Use program
examines the impact of biomass requirements and land-use changes on the biomass resource base. Biomass
projections are based on the inventory of wood stocks and yields, crop yields, crop residue availability, and dung
production, at various levels of spatial detail. The Environment program links the physical processes created in
the scenario programs to EDB, to track the emissions loadings and impacts of alternative scenarios. The
Evaluation analysis includes the impacts of technology and project costs, inflation, discount rates, and foreign
exchange components of each option, and can account for either market or shadow prices, as well as
environmental externality costs, if included.
5.3
Step-by-Step Guide to Performing Energy and Environmental Analysis
Developing Loadings Inventories and Projections for the Energy Sector
99
Figure 5.1 below, and the text that follows, present the general steps in perform energy and
environment planning studies (as summarized in Box 1.1), and indicates where LEAP and EDB can be
used to assist the planning process. Once again though the steps below specifically
Figure 5.1:
FLOW DIAGRAM FOR PREPARING ENVIRONMENTAL LOADINGS PROJECTIONS
IN ENERGY-ENVIRONMENT ANALYSIS
STEP 1:
Determine Planning Goals
STEP 2:
Investigate Energy Use Patterns,
Assemble Available Energy Data
STEP 3:
Prepare Baseline Scenarios
POSSIBLE TOOLS:
LEAP:
Demand,
Transformation,
and
Biomass
Programs
Cost Curves
Surveys
Interviews
STEP 4:
Prepare Alternative Scenarios
STEP 5:
Collect Environmental Data and
Estimate Loadings
STEP 6:
Analyze Policy Options and Implications
EDB, LEAP
Environment
Program
LEAP Evaluation
Program,
Macroeconomic
Analysis,
Financial Analysis
100
A Guide to Environmental Analysis For Energy Planners
5.3.1 Determine Planning Goals
The first step in assembling a LEAP/EDB energy/environment planning analysis, or similar
analyses using tool or framework, for that matter, is to determine what information you, as a planner, wish
to obtain from the planning exercise. While this may seem obvious, a clear statement of planning goals
can help shape your study, including the form of the model you will create and what type of data you will
collect, and as such, allow you to spend your time on activities that are directly oriented toward providing
the information you need most. For example, if what is needed is an all-sector overview of different
energy futures for the country, the best approach might be to develop a model structure that allows the
testing of broad policy instruments, and to gather energy and environmental data that spans all of the
sectors of the economy, but does not go into great detail in any one sector. Conversely, if what is needed is
very specific information on the potential outcome of applying policies to a particular sector, such as the
transport sector, you will want to create an energy database that allows you to test very specific policies
(such as taxes on particular fuels, subsidies to electric or alcohol-fueled vehicles, or import policies
designed to increase the fuel efficiency of the vehicle fleet), for which you would seek detailed data
describing the sector you wish to concentrate on, and less-detailed data for other sectors.
On the environmental side, your consideration of planning goals should include, for example a list
of the pollutants (and environmental impacts resulting from pollutants) that you want to learn about.
Urban air pollutants, acid gases, or greenhouse gases, for example--each with impacts as described in
Section 2 of this study--might be a focus of your study. You may be looking to create an inventory of
emissions in order to apply techniques, like those described in Section 6, that are used to estimate the
ultimate environmental impacts of the emissions in the inventory.
For “Country X”, the assumed planning goals are to prepare a model structure that will serve as
the basis for an inventory of present and future emissions of air pollutants, particularly greenhouse gases,
and can also be used to explore different options to reduce the country’s emissions of GHGs and other
pollutants.
5.3.2
Investigate Energy Use Patterns and Assemble Available Energy and Environmental Data
One way to begin this task is to draw a crude diagram or table showing what energy end-uses are
important in your country or region (or those which end-uses you wish to include in your modeling effort),
which energy resources are being used or are available to supply those end-uses, and what categories of
environmental loadings or impacts result from the operation of the energy system you are looking at. This
chart or table will then provide a guide to gathering the data that you will need to inform your study.
Information on the patterns of energy flows may be available from existing national or state energy
balances, from earlier narrative descriptions of the energy system you are modeling, from existing energy
surveys, and from your fellow planners and engineers who are familiar with the way that the energy system
works.
The types of energy and environmental data that you will be trying to locate may include (with the
level of detail depending on the focus of your study):
•
Energy End-Uses, including data that conveniently describe how much of a given fuel is used to meet
an end use, and the distribution of different energy-using devices in your energy system (for example,
what fraction of rural household stoves use wood, and what fraction kerosene?).
Developing Loadings Inventories and Projections for the Energy Sector
101
•
“Activities”, or quantities such as population, the number of households, income, changing
technologies, and other parameters that are likely to affect the demand for energy in the future.
•
Energy Supplies--including primary resources such as coal in the ground, fuel imports, exports, and
losses, and important fuel production and conversion processes such as coal mining, oil and gas
extraction, and petroleum refining, and charcoal manufacture.
•
Land use and biomass stocks and yields
•
Costs of energy technologies, fuels, energy resources, and environmental resources (e.g. emissions
values). Technology costs will include both the non-fuel costs of operating a given type of
equipment, and the capital costs of that equipment.. Resource costs can include costs of imported
and domestic fuels, as well as the export prices for fuels sold abroad.
•
Qualitative, and especially quantitative data on the environmental impacts of energy production and
use.
•
Existing forecasts of key parameters that will affect future energy use in your country, state, or
region. These forecasts could include estimates of future economic and industrial activity, future
trends in transport, expansion plans for electric and petroleum utilities, and forecasts of population
and household size
Sources for the types of data listed above include National or State data compendia and other
publications; international (for example, United Nations, World Bank, or IEA/OECD) statistics; articles,
reports, and books from the academic sector; and, in some cases, statistics from the commercial and
industrial sector. Where data are sparse, interviews with people familiar with activities in particular
sectors can help to provide at least approximate information to fill in the gaps.
Some of the key characteristics of the demography, economy and energy system in Country X are
presented in Box 5.3, below.
102
A Guide to Environmental Analysis For Energy Planners
Box 5.3: Key Characteristics of Hypothetical Country “X”
•
•
•
•
•
•
•
•
•
•
•
•
A middle-income developing economy of 40 million people. (~$600 GDP per capita);
GDP is expected to grow at 3.5% per year through, while population is expected to grow at 2.5% per
year;
As of 1990, 30% of the country’s 8 million households reside in urban areas, a fraction which is
expected to rise to 45% by 2030. Due to decline numbers of persons per household from 5 to
around 4, the number of households increases at 3.0% per year, faster than population;
Low but growing per-capita energy use (7.5 GJ total end-use energy per capita in 1990);
A relatively diversified economy, with significant commercial and manufacturing activity, and energyintensive, basic materials industries (iron and steel, cement, chemicals, and paper and pulp);
A mostly oil-based energy system, with considerable use of traditional fuels, particularly in rural
areas;
A current stock of electricity generation facilities that includes hydroelectric (25% of 1990
generation), oil-fired (25%), and coal-fired (50%) plants;
Expected increasing reliance on indigenous coal to fuel a growing electricity demand;
Access to imported gas and some indigenous renewable resources;
Irrigated agriculture, which accounts for about 10% of base year electricity demand;
Currently modest but rapidly growing demand for personal transportation services; and,
An ongoing program of rural electrification, with 95 percent of the households in the country
expected to have electricity service by 2030, compared with 65 percent in 1990.
5.3.3 Prepare Reference Case Projections
The preparation of reference case projections, using the data you collected in step B, above as a
"base year" starting point, involves several intermediate tasks. The first of these is to design a structure
for the model of your energy system. Here, you will want to bear in mind the modeling objectives you are
trying to achieve (as defined in step A), as these objectives will help you decide, for example, what level of
detail to use in your LEAP Demand data set for each sector, or which are the important energy supply
technologies that could change in the future, and thus should be included in your Transformation data set97.
Once your LEAP data structures are mapped out, the next task is to load the data you collected
during step B into LEAP, and assess the need for additional information. Quite often you may find, while
entering data into LEAP, that the data you have collected lack sufficient detail for some sectors or enduses, or for certain energy supply technologies or resources. In addition, you may find that some of the
data you have collected are inconsistent. In either case, you may need to return to step B to seek additional
data or to clarify existing information.
Having loaded the information you have available into LEAP, the next task is to run the Demand
and Transformation modules of LEAP, review the results, and go back and "de-bug" your data structures
as required. Here it is very important to look carefully at your results. Is the total energy consumption
for the base year about what you expected? Are there unexpected increases or decreases in the use of
certain fuels or in energy use in certain sectors? Are the energy unit what you expect? If you note
problems, you will need to return to your LEAP Demand and Transformation models and correct them.
Happily, as LEAP results often take only seconds to produce, it is relatively easy and quick to check the
results of your data corrections. Here it should be emphasized that the estimates of environmental loadings
are based on the LEAP estimates of fuel use and production, so it is important to make sure that your
97Again, the reader is urged to consult the LEAP User Guide for more detail on how data are entered into LEAP and how
LEAP models are built.
Developing Loadings Inventories and Projections for the Energy Sector
103
energy results look reasonable before continuing on to calculation of pollutant loadings and other direct
environmental impacts.
For Country X, the set of reference or “base case” scenario assumptions used is described in Box
5.4.
Box 5.4: Reference Case Scenario Assumptions for Country X
•
•
•
•
•
•
•
•
•
•
•
•
Population grows at 2.5 %/year through 2030. Due to an ongoing reduction in the size of households, the
number of households grows at 3.0%/year. The share of households in urban areas increases from 30% in
1990 to 45% in 2030;
National GDP grows at 3.5%/yr. through 2030, with faster growth in the commercial or services sector
compared to the industrial sector;
Rural electrification increases the number of electrified rural households from 65% to 95% from 1990 to 2030;
Rising standards of living increase the saturation of electric end-uses (refrigeration, air conditioning,
television, etc.), the level of lighting usage (up at 1.0% per year), and the rate of switching from traditional to
modern cooking fuels. With the exception of slower improvements in traditional cook stove efficiency
(0.3%/year), the energy efficiency of household devices improves at about 0.5% per year, reflecting the natural
replacement of older with newer more efficient appliances;
Energy demand in the commercial, agricultural, and most industrial sectors grows with sectoral value added
(GDP). The baseline energy intensity (energy use per unit value added) decreases by 0.5%/year;
Personal transport services, indicated by passenger-kilometers traveled per capita, increases at 2.5%/yr. until
2010 and 2.0%/yr. beyond that. There is a gradual shift from public transportation to private vehicles. Private
passenger vehicles are assumed to have an average natural increase in energy efficiency of 0.75%/year, while
the natural increase in efficiency of buses, trains, and planes is 0.5%/year;
Freight transport (tonne-km per capita) grows at 2.0%/year. Freight transport undergoes a slow shift from
smaller trucks to larger trucks and from road and water-borne freight to air and rail freight. Road freight still
maintains a dominant 78.5% share of freight transport by 2030, only a modest reduction from its 1990 level of
83%;
About two-thirds of new electric capacity is coal-fired, the remaining one-third is oil-fired. Existing facilities
are retired at the end of their planned lifetimes, with the exception of hydroelectric facilities which are
maintained;
Domestic coal production capacity is expected to increase almost four-fold over 1990 levels by 2030;
No new oil refining capacity is added;
The real price of crude oil and refined petroleum products increase modestly, averaging 0.8%/year (real)
through 2030. (Based on UNEP, 1994b); and,
Indigenous renewable resources (wind, solar, and biomass) remain untapped, except for continued use of
traditional woodfuels and existing hydroelectric capacity.
5.3.4 Prepare and Run Alternative Scenarios
At this point you have mapped out and run your "base case" LEAP projection. The next step is to
define and run some energy scenarios that address some of the planning goals that you defined in step A.
LEAP scenarios are defined by changing one or more of the values in your base case data set that affect
future energy demand and/or fuel supply. You might wish to explore, for example, what will happen if the
population of your country or region grows more slowly than anticipated, or more quickly. You would do
this by changing the population or household growth rates built into your base-case data set. You might
also ask what the implications would be of increased electricity use in the residential sector. This could be
modeled by increasing the fraction of households using electricity for certain end-uses, and decreasing the
fraction of homes using other fuels. In any event, the goal in this step is to estimate the effects on energy
104
A Guide to Environmental Analysis For Energy Planners
demand and supply of different "futures" that your country or region might face, or of policies that might
be undertaken to shape a different energy future.
For Country X, a GHG mitigation scenario was fashioned incorporating the following GHGreduction measures:
•
•
•
•
•
•
•
•
•
Residential lighting efficiency improvements. A program would encourage the replacement of
incandescent with much more efficient compact fluorescent light bulbs in both urban and rural
households.
Residential refrigerator efficiency improvement. A standards or import tariff program would
improve the efficiency of new refrigerators on the market.
Improved industrial and commercial lighting and motor drive efficiency. This could be
achieved through standards, incentive programs, tariff and import policies, or other policy
instruments.
Switching from coal and oil to natural gas for industrial sector process heat applications.
Natural gas furnaces and boilers produce less CO2 per fuel consumed, and are often more
efficient as well, requiring less fuel consumption.
Improving vehicle efficiency for automobiles, light and heavy trucks, and buses. This could be
achieved through standards, incentive programs, tariff and import policies, or other policy
instruments.
Replacement of new coal-fired electric plants with more efficient natural gas combined-cycle
facilities that have lower CO2 emissions per unit electricity output. Natural gas would be
imported via pipeline from a neighboring country.
Windfarms for electric generation. Most added capacity will occur between 2010 and 2030, by
which time the technologies for power generation from wind are expected to be mature and
cost-competitive in most applications.
New nuclear power stations. These would be the first nuclear units in the country.
Solar photovoltaic electric generation.
Note that these measures also help meet many other planning goals, including reduction of fuel
imports, more intensive utilization of local renewable resources, reducing local pollutant emissions by
moving to “cleaner” and renewable fuels, and generating local expertise in the installation and use of
renewable energy systems. Each measure has its associated costs, characteristic energy resource needs per
unit of energy services provided, and environmental impacts.
For Country X, these measures were assumed to be “penetrate” the energy system, that is, be
implemented, at different rates, beginning in 1994 or thereafter. For instance, for agricultural pumpsets, it
was assumed that approximately one-quarter of all units would be replaced in 20 years, or an overall
penetration rate of 1.25% per year. Since improved pumpsets could reduce electricity consumption by
40%, the overall energy intensity for agricultural pumpsets declines at 0.5% per year. As the result of
similar sets of assumptions for efficiency improvement, energy intensities for other targeted end-uses
decline at rates of 0.25% per year (commercial/industrial motors) to almost over 2% per year (residential
lighting, first 20 years) relative to baseline scenario levels. For industrial fuel switching, it was assumed
that about 1% per year of coal and oil use applications could be switched to natural gas, up to 20% by
2010 and 40% by 2030. For the power sector, it was assumed that combined cycle gas facilities could
replace about 40% of planned coal additions, leading to 1000 MW of gas-fired capacity by 2010 and 3600
MW by 2030. The wind power potential was limited to 200 MW by 2010 and 1500 MW, or
approximately 9% of total installed capacity, in 2030.
Developing Loadings Inventories and Projections for the Energy Sector
105
5.3.5 Collect environmental data and estimate loadings
Estimates of environmental loadings calculated with LEAP and EDB are only as good as the
energy and environmental data on which they are based. In an ideal world, you would be able to use your
energy data, as entered in LEAP, with emissions factors calculated based on the measured performance of
equipment, appliances and vehicles in your own area. While this is, in practice, not possible--few
countries at present have undertaken extensive measurements of emission factors--you should make an
effort to collect what local emission factors and direct impact data are available for your area. This may
involve contacting local researchers in the environmental field and asking for their test results, or locating
studies that have investigated the environmental characteristics of energy technologies similar to those used
in your country. When these types of data have been assembled, they can be entered into EDB. It is a
good idea to check existing EDB emissions coefficients for similar devices (if available) as you enter your
local data, as such cross-checking may turn up anomalies or errors in the emission factor data that could
prove troublesome later on.
Once you have entered any available local emission factor data into EDB, you are ready to "link"
EDB to your LEAP data set. This is done from within the Demand and Transformation modules of LEAP
by indicating, for each appropriate device in the Demand program, and for each different type of process in
the Transformation program (for example, for each different type of electricity generation facility), from
which EDB "source" category LEAP should take emissions coefficients. Here some words of warning are
in order. First, your emissions/impacts inventory will be only be as complete as the EDB categories to
which you have linked your LEAP data set. It is perhaps obvious that if you link only a small fraction of
the Demand devices in your data set with EDB sources, your reports in the Environmental Evaluation
module will only reflect a fraction of the true emissions or impacts in your country. Note here that some
LEAP devices may not need to be linked. End-use consumption of electricity, for example, generally has
few directly associated emissions or impacts (the impacts of producing electricity are, of course, not
negligible, and are typically captured by EDB links through the LEAP Transformation module), and thus
electricity-using devices are usually not linked to EDB source categories. Section 4 of this document
provides additional guidance and background on the choice of emission factors.
Less obvious, but equally important, if the EDB source category to which a particular LEAP
device or process is linked does not provide complete coverage of the emissions or impacts you are
interested in, your inventory will be incomplete. For example, you may, in the process of making links,
discover an EDB category that appears to be a good match to a LEAP Demand device, but when you check
the emission factors available for that category (as you browse through EDB) you may find that the
particular EDB source category you have linked to provides only one or two emission factors, and does not
cover one or more key pollutants that you wish to include in your inventory. It is necessary to both
perform links to all of the LEAP devices and processes that are likely to produce emissions or impacts, and
to make sure that your links are to EDB source categories that provide appropriate coverage.
For Country X, we created links to EDB using a selection of mostly generic EDB source
categories, but we were careful to select source categories that provided good coverage of the greenhouse
gases, that is, source categories with emission factors for most or all of the important greenhouse gases that
we wanted to study.
Once links between EDB and your LEAP Demand and Transformation data sets have been
prepared, the final step is to run the Environmental Evaluation module to calculate the loadings and direct
health and safety impacts that are projected to result from your base case and alternative LEAP scenarios.
106
A Guide to Environmental Analysis For Energy Planners
As with the LEAP energy results, you should review the output of the Environmental module to make sure
that there have been no major errors in data entry or in linking. Use the reporting features of the program
to focus on results by sector, subsector, end-use, fuel, and transformation process. Are there areas in
which you expect emissions or impacts of certain types, but none are reported? If so, you may have
missed making some links, or some key EDB coefficients may be missing. On the other hand, if certain
results look too high, and you have satisfied yourself that the energy data in LEAP are not in error, it may
be that one of the user entered or Core EDB coefficients are wrong98.
Key results of our Country X analysis, for both the “Baseline” and “Mitigation” scenarios, are
shown in Table 5.2, below.
Table 5.2:
Selected Physical Indicators for Country X Scenarios
Final Consumption (Million GJ)
Petroleum Products
Electricity
1990
296.9
151.7
65.2
Baseline Scenario
2010
2030
548.5
1064.8
318.4
667.1
137.4
281.7
Mitigation Scenario
2010
2030
505.5
898.7
279.7
524.6
125.7
235.5
Primary Energy (Million GJ)
Coal
Natural Gas
Petroleum Products
469.5
168.5
0.0
216.8
926.2
430.4
0.0
410.9
1851.0
936.7
0.0
810.3
810.9
284.4
64.7
366.7
1429.5
429.3
223.8
663.0
CO2 Emissions (Million Tonnes)
CO Emissions (Thousand Tonnes)
CH4 Emissions (Thousand Tonnes)
NOx Emissions (Thousand Tonnes)
26.8
477.2
84.1
95.9
57.7
819.6
214.5
180.6
124.1
1,623.0
419.8
371.3
47.9
740.2
143.5
159.7
86.5
1,305.2
219.2
287.9
The steps above provide a general guide to energy and environmental analysis using LEAP and
EDB. One thing to keep in mind in all applications of LEAP and EDB is that LEAP is designed so that it
is easy to update data sets, recalculate results, check the new results, and update the data again. This
means that you can easily start out using what data you have available, and build on it later, and also
emphasizes that importance of thinking critically about the data you gather and the results you produce to
make sure that they are both as accurate as you can make them, given information and other resource
constraints, and also that they meet your policy evaluation requirements. In sub-section 5.3, below, we
present a concrete example of how the steps listed above have been implemented in producing a specific
energy/environment study of reference and alternative scenarios of energy production and use in Costa
Rica. For your reference, Box 5.5 provides a summary of the way that calculations are carried out in
LEAP and EDB for an analysis like the Country X and Costa Rica examples presented here.
98Another possibility is that there is an error in the fuel composition data entered in LEAP. For some types of emission
factors, emissions depend in part on the fraction of a particular element or substance present in the fuel. Sulfur oxide
emissions, for example, will often depend on the fraction of sulfur in the fuel. If this fraction has been entered incorrectly, all
links to EDB coefficients that reference this fraction will be in error.
Developing Loadings Inventories and Projections for the Energy Sector
107
Box 5.5: The Flow of Calculations in the LEAP/EDB System
In the LEAP/EDB system, the flow of calculations in proceeding from initial assumptions (entered
or selected by the user) to final estimates of pollutant loadings and other direct environmental impacts
can be summarized as follows:
Basic Equations:
Energy Consuming Activity x Device Share x Energy Intensity = Energy Use by Device
Energy Use (device) x Loading Factor (effect, device) = Loadings
Where:
Energy Consuming Activity = An activity or energy service for which fuel is consumed, for example, a
vehicle-kilometer traveled
Device = Any process or technology that produces, consumes, or loses energy (such as electric
transmission and distribution).
Device Share = The fraction of an activity served by a particular device, such as the fraction of vehicle
kilometers traveled by diesel buses
Energy Intensity = The amount of fuel used to provide a unit of the desired activity or energy service-liters of diesel per kilometer traveled, for example.
Energy Use = Measured in tonnes (or other physical units) of fuel produced, consumed, or lost by a
device.
108
A Guide to Environmental Analysis For Energy Planners
Box 5.5 (continued):
In the above, the model of energy production and use (including energy consuming activities,
device shares, and energy intensities) is constructed in LEAP, and "links" are made from within LEAP to
match devices to sets of loading factors (for each "source") in EDB. Once these links are complete,
loadings are calculated from within the Environment Program of LEAP (see Box 5.2, above).
At this point, several key features of the LEAP/EDB of approach should be understood in order
to appreciate both the limitations and the capabilities of the software:
1. The calculation structure of LEAP/EDB assumes a linear relationship holds between energy use
(consumption, production, or losses) and environmental loadings.
2. The mitigation measures that can change loading factors can be grouped into two categories:
changing technologies and operating practices (includes adding pollution control technologies to
existing equipment, or changing the composition of the fuel consumed). These can be handled in
LEAP by changing, over time, to greater use of devices with different sets of loading factors (e.g. by
shifting the composition of your future vehicle fleet to include a higher proportion of cars equipped
with NOx-reducing catalytic converters) or by changing fuels, say, to lower sulfur coals, to reduce SOx
emissions.
3. LEAP and EDB do not, at present, provide any modeling of environmental impacts beyond direct
loadings of pollutants and selected direct health and safety impacts. Loadings reports from the
Environmental Evaluation Program of LEAP can, however, be used as input files for software
programs outside of the LEAP system that are designed to estimate impacts.
4. EDB does not, at present, provide information on non-quantifiable impacts of energy production and
use (such as the aesthetic impacts of a power plant on local vistas).
5. Through the Cost-Benefit Evaluation Program of LEAP, it is possible to attach monetized
environmental costs to pollution loadings estimates, and thus bring environmental costs directly into
the overall cost-benefit analysis of energy scenarios99
6. As LEAP and EDB do not provide coverage of most non-energy activities, you should keep in mind
that an evaluation of the energy sector provides only part of the picture, and the most important
environmental problems may lie elsewhere. LEAP does, however (through the Biomass program),
provide the capability to study the impacts of land use changes--whether energy or non-energyrelated, on the biomass resource base.
5.4 A Case-Study Application of LEAP and EDB: Costa Rica
Using much the same approach as outlined above, LEAP and EDB was used as a software tools in
a forward-looking energy/environment planning study focusing on Costa Rica. Key modeling choices,
input data assumptions, and results are described in the summary below. For another example of the
application of LEAP and EDB, please see the study of the United States contained in America's Energy
Choices Investing in a Strong Economy and a Clean Environment (Union of Concerned Scientists et al,
1991). In the summary of the Costa Rica study that follows we have indicated how the study techniques
used correspond to the suggested Steps in Preparing Environmental Loadings Projections In EnergyEnvironment Analysis as listed in Figure 5.1.
99Note that while this procedure for incorporating environmental costs into a cost-benefit analysis, while seemingly
straightforward, requires a good deal of thought in the choice of the monetary values to be attached to loadings of different
types. While attempts have been made to make the choice of these values as objective as possible, this choice remains
primarily a subjective one.
Developing Loadings Inventories and Projections for the Energy Sector
109
5.4.1 Costa Rica100
In 1991 and 1992, SEI-B and the Latin American Energy Organization (OLADE) collaborated on
a preliminary application of LEAP/EDB in Costa Rica. Some of these data used for this analysis were
available at OLADE, as part of the Sistema de Informacion Economica Energetica (SIEE), and additional
documents were collected by SEI-B and OLADE personnel during visits with the Costa Rican host agency
for the project, the Dirección Sectorial de Energía (DSE) in San Jose. In the remainder of this section, we
briefly introduce the context for energy and environment planning in Costa Rica, outline the different
energy scenarios tested, and report on key results -- future energy use, emissions of pollutants to the
environment, and estimated costs -- of these scenarios using the methodology outlined above. For full
details of this study, the reader is urged to see the complete report on the Application, available both in
English and Spanish. (Von Hippel and Granda, 1992)
The Energy and Resource Situation in Costa Rica (Step 2 in Figure 5.1)
Costa Rica covers 51,000 square kilometers (LANL, 1987). Half of the population of 2.72
million lives in urban areas (SIEE; OLADE, 1991). The overall population density is 53 people per km2,
one of the lowest in Central America. The rate of population growth is just over two percent per year
(World Bank, 1990), also one of the lowest in the Central America region. The population in urban areas
is increasing somewhat faster than the population as a whole.
Table 5.3 shows the breakdown of 1988 energy use in Costa Rica by sector and by fuel. Biomass
fuels ("Firewood" and "Other") provide 42 percent of the final energy consumed in Costa Rica, with
petroleum fuels providing 41 percent and electricity 15 percent. All crude oil and refined petroleum fuels
are currently imported. Electricity production and capacity is mostly hydroelectric. The residential sector
is the largest consumer of energy (44 percent), of which nearly three-quarters is firewood. The transport
sector contributes 32 percent of total fuel demand, and consumes nearly 80 percent of all of the refined
petroleum products used in the country. The industrial sector accounts for 23 percent of consumption.
Overall, per capita energy consumption has remained relatively stable between 1984 and 1989, at
4.2 to 4.4 bpe101/person, down from its highest level of 4.6 bpe/person in the late 1970's. The energyeconomic energy intensity, in bpe/$1000 US (1980) has decreased slightly from 3.2 in 1985 to 3.0 in 1987
to 1989. Since 1982, transport fuel consumption has risen steadily at an average of 8.0 percent per year
(SIEE; OLADE, 1991).
100 Portions of the following text were excerpted from Von Hippel and Granda, 1992.
101 Barrels of petroleum equivalent (BEP in Spanish).
110
A Guide to Environmental Analysis For Energy Planners
Table 5.3:
Energy Consumption in Costa Rica (1988)
in Barrels of Oil Equivalent (BOE or BEP)
Sector
Transportation
Industrial
Residential
Commercial/
Public
TOTAL
Percent of Total
Petroleum
Products
3940
946
134
0
Electricity
Firewood
Other
Total
4
525
1291
57
0
223
3907
0
0
1067
0
0
3944
2775
5393
57
5020
1877
4130
1067
41%
15%
34%
9%
1216
9
100%
Percent
of Total
32%
23%
44%
0.5%
Since the 1960s, there has been no fossil fuel production in Costa Rica. Costa Rica has extensive
hydropower resources that are as yet unexploited, and geothermal development is underway in the western
part of the country at Miravalles. The supply of biomass fuels for residential needs in Costa Rica is
currently adequate, though future firewood supplies could be limited somewhat by ongoing deforestation,
which is driven by expansion of agriculture, and by changes in the way coffee plantations are cropped.
Solar energy is an attractive option for Costa Rica, but frequent cloud cover limits the applicability of
technologies requiring direct solar radiation. Wind energy resources in Costa Rica, surveyed in the early
1980's, could contribute a small portion of Costa Rica's electricity needs, particularly in isolated areas.
The primary challenge for the Costa Rican energy and resource sectors in the coming years will be
to provide the fuels and energy services required for economic development given 1) limited availability of
funds for capital investment 2) potential environmental and resource constraints on expansion of energy
supply such as changing land-use patterns, continued deforestation, limits on hydropower development,
and, conceivably, climate change agreements102, and 3) problems obtaining the necessary foreign exchange
funds to pay for imported fuels. The preliminary application of LEAP/EDB was designed to test some of
the options available for meeting Costa Rica's energy needs (Steps 1, 3, and 4 in Figure 5.1).
Five exploratory scenarios included:
•
A Base Case scenario that assumes future energy consumption is determined primarily by the
level of economic development of the country and by the growth rate of the population. The dependency
of energy demand on economic development was modeled, quite simply, as a direct relationship between
demand and GDP or population, and in some cases (such as transportation), both. Growth in this case
is based on the supposition that the economic trends of the 1980s will continue.
•
A Continuidad scenario that departs modestly from the Base Case scenario by assuming a
stronger economic growth rate, increasing in the intensity of useful energy consumption (heat energy
delivered in the form of steam, for instance) in the industrial sector, and maintaining constant energy
intensities in other sectors.
102 Of course, depending on its final form, Costa Rica could conceivably benefit from an international climate change
agreement.
Developing Loadings Inventories and Projections for the Energy Sector
111
•
A Transformación scenario that reflects support for development from outside Latin America
and allows Costa Rica to invest in continued social and technological development that, in turn, reduces
the energy intensity of many energy activities, especially in the industrial and transport sectors.
•
A MIPE/MEDIO scenario that closely matches the results of a mid-range scenario from
DSE's own MIPE planning model (DSE, 1990). Major modifications of the Base Case values to
achieve this match included higher projections of GDP growth, higher electricity use in the services
sector, higher population/household growth, higher electricity use for cooking in residences, an increase
in the demand for transport services, and a shift toward more use of diesel fuel.
•
A MIPE/MEDIO + Efficiency improvements scenario that is based on the MIPE/MEDIO
scenario described above, but includes the improvements in energy efficiency in each of the major
sectors. These improvements are based on readily available technologies.
Future capital investments in energy supply facilities -- electricity generation plants, for example -were assumed in the Base Case to follow the National Generation Expansion Plan (ICE, 1991), and similar
plans for the petroleum refining sector. A large (3-fold) increase in electric generation capacity is foreseen
under this Plan, with about 75 percent of the added capacity to be in the form of hydroelectric and
geothermal plants, and the remainder fossil-fueled.
In the Base Case scenario, wood consumption remains relatively steady, while demand for most
fossil fuels and electricity increase. Figure 5.2 shows the overall fuel demand for each of the five cases
over time. Demand in the MIPE/MEDIO case is far higher than the other cases, with the largest percentage
differences by sector appearing in the services, residential, and industrial cases. It is interesting to note
that just by adding a few simple efficiency measures, overall year-2010 fuel demand in the MIPE/MEDIO
+ Efficiency case is reduced almost 20 percent relative to the MIPE/MEDIO case.
Million GJ
Figure 5.2:
Total End-Use Costa Rica Energy Consumption, Five Scenarios
180
160
140
120
100
80
60
40
20
0
BASE CASE
CONTINUIDAD
TRANSFORMACION
MIPE/MEDIO
MIPE/MEDIO + EFF
1989 1995 2000 2005 2010
Using methods described in Section 4 of this document, "devices" or sources of environmental
emissions, for which emissions data are available in the Environmental Data Base, were matched with fuelusing devices (and energy transformation equipment such as power plants) called for in the scenarios
112
A Guide to Environmental Analysis For Energy Planners
described above (part of Step 5 in Figure 5.1). Using these data, estimates of current and future emissions
of several common air pollutants were obtained. Results for four of these pollutants -- carbon dioxide
(CO2), carbon monoxide (CO), hydrocarbons, and nitrogen oxides (NOx), are presented in Figure 5.3. The
MIPE/MEDIO scenario produces the highest level of emissions of each of these pollutants by the year
2000, while the "Transformación" and MIPE/MEDIO + Efficiency Scenarios are the most effective,
overall, in reducing emissions, principally because both involve increases in energy efficiency and,
typically, newer, less polluting equipment.
Figure 5.3:
Selected Air Emissions Results for Five Scenario Tested
7000
6000
5000
4000
3000
2000
1000
0
TOTAL CO
EMISSIONS: FIVE
SCENARIOS
BASE CASE
Million kg CO
Million kg CO2
NET CO2 EMISSIONS: FIVE
SCENARIOS
CONTINUIDAD
TRANSFORMACION
MIPE/MEDIO
MIPE/MEDIO + EFF
1989
2000
2010
1989
50
40
30
20
10
0
2000
2010
2000
2010
TOTAL NOx EMISSIONS:
FIVE SCENARIOS
Million kg NOx
Million kg HC
TOTAL HYDROCARBON
EMISSIONS: FIVE
SCENARIOS
1989
250
200
150
100
50
0
50
40
30
20
10
0
1989
2000
2010
In addition to the energy demand, energy supply, and environmental emissions elements described
above, the Costa Rica study also examined, using the methodology contained in the LEAP Biomass
Module, two different scenarios of changing land uses. These scenarios integrated the effects of demand
for biomass fuels, pressures on land due to increasing urban and rural populations (and the need for food
by those populations) and other ongoing shifts in land use. The Base Case scenario assumed that the
average deforestation rates encountered over the last 20 years would continue, while a second Biomass
module scenario assumed that trends in (reduced) deforestation noted over the last few years would hold
instead. In the Base Case, forest stocks in Costa Rica were estimated to be substantially depleted by 2010,
while land use changes when the more recent trends in deforestation were assumed were much more
modest, with small increases in the land devoted to annual crops, pastures, and settlements being offset by
an approximately 10 percent decline in forest area.
Differences in costs and benefits between two scenarios, the MIPE/MEDIO case and the
MIPE/MEDIO + Efficiency Case, were examined (part of Step 6 in Figure 5.1). The categories of costs
and benefits considered for each case were the costs of energy end-use equipment (stoves, automobiles,
Developing Loadings Inventories and Projections for the Energy Sector
113
etc.), the costs of energy transforming equipment and facilities (such as power plants), the costs of
domestic, imported and exported fuels and resources (especially oil products), and the costs of
environmental externalities. These cost categories correspond to, respectively, the "Demand",
"Transformation", "Resource" and Environment" elements in Figure 5.4 below.
500
0
ENVIRONMENTAL
-500
-1000
RESOURCE
-1500
TRANSFORMATION
-2000
DEMAND
-2500
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
Discounted Million $1990
Figure 5.4:
Cumulative Costs (Positive Values) and Benefits (Negative Values) of Shifting
from the Reference Scenario to the Alternative Scenario
(MIPE/MEDIO + Efficiency)
When efficiency measures were added to the MIPE/MEDIO Case, electricity demand was reduced
sufficiently that several of the planned generating plants could be avoided. The combination of the
MIPE/MEDIO case with the Base Case generation expansion plan form the "Reference" case shown in
Figure 5.4 below, and the combination of the MIPE/MEDIO + Efficiency Case with reduced construction
of power plants form the "Alternative" case. As Figure 5.4 shows, the benefits of increasing energy
efficiency far outweigh the costs, particularly when environmental costs are factored in (using monetary
externality values described later in this paper). The total net cumulative discounted value (using a real
discount rate of approximately 4 percent), in 2010, of the transformation, resource, and environmental
benefits of shifting to the higher-efficiency scenario are estimated as $640 million, $415 million, and $950
million, respectively ($1990). These benefits are "purchased" at a cost of $334 million, which is the extra
cost for improved-efficiency demand devices. Summing over the four types of costs yields a net benefit of
about $1.67 billion. If environmental costs are left out of the analysis, there is still a net cumulative
benefit of about $720 million in moving to the Alternative scenario. Significantly, there are also
considerable foreign exchange benefits to Costa Rica in adopting energy efficiency measures, principally
because the costs of oil imports are avoided. It should be noted that this type of analysis, where both costs
and benefits are ignored after a specific cut-off date (here 2010), tends to reduce the net benefits accruing
because of investments in efficient demand devices, as it ignores those benefits of demand-side investments
that occur after the end of the analysis period. For example, an efficient industrial boiler purchased in
2008 will still be saving fuel resources in the year 2111, but these resource savings are not counted in the
total benefits calculation.
The excellent availability of data in Costa Rica, coupled with the existence of an able and very
helpful in-country collaborating agency (DSE), made the Case Study described above a very fruitful one.
The case study demonstrated the usefulness of the LEAP/EDB methodology for integrated
114
A Guide to Environmental Analysis For Energy Planners
energy/environment planning, and, in a preliminary way, pointed up policy opportunities that Costa Rica
might pursue to meld the goals of development, cost containment, and increasing energy efficiency.
While Costa Rica faces many of the same problems as other countries in the region, including
excessive debt, reliance on imported petroleum and petroleum products, and deforestation, the country is
blessed with a low population density, fairly abundant resources, and a sophisticated planning bureaucracy
well-versed in appropriate planning techniques.
Scenario analysis shows that relatively robust growth in energy demand in Costa Rica can be
accomplished without exceeding available resources (as in the MIPE/MEDIO scenario), although payments
for major new energy facilities may be problematic. While the scenarios explored in this report do not, of
course, begin to explore the various options open to Costa Rica, they suggest that the country has the
possibility to provide a very positive development model for the countries of the region. To some extent,
however, Costa Rica, due to its small internal demand for major consumer goods, must remain a prisoner
of international technology choices. The prime example of this is in the transport sector, where use of
automobiles designed and produced in larger nations generates much of the pollution and foreign exchange
problems in the country.
As part of the project, a Working Group was formed, drawing its members from six different
Costa Rican government organization involved in energy planning. The task of this working group was to
help evaluate the usefulness of the LEAP/EDB methodology in a Costa Rican context while they gained
familiarity with the approach. One quite rewarding aspect of the Working Group, was that it provided an
apparently unique opportunity for mid-level planners in the ministries represented to sit down to 1) evaluate
a single tool together, and 2) discuss the status and approach of planning in their organizations. The
interesting general discussion about planning that arose pointed up one of the strengths of LEAP; since it is
a tool that crosses the traditional boundaries of planning ministries, it can serve as a catalyst for greater
coordination and cooperation between the different organizations that have the responsibility for guiding
energy/environment policy in a country.
5.4.2 Environmental Analysis and Valuation in the Costa Rica Study
The environmental analysis and valuation methods employed in both studies were rather similar.
First, emission factors were developed using Environmental Data Base. For the United States study the
Core data of EDB were augmented with available emissions data that represent both existing and emerging
local technologies and operational practices.
The two greatest difficulties in a quantitative environmental approach are the integration of factors
that are impossible or difficult to measure or generalize (such as ecological damage, soil degradation, and
aesthetic impacts), and the comparison across seemingly incommensurate impacts (such as balancing
human health, ecological, and economic costs and benefits). In addition, there can be considerable
uncertainties in identifying and generalizing relationships between emission and other environmental insults
(e.g. the amount of land flooded by construction and operation of a hydroelectric station) and the actual
damages that result. In particular, for energy sources whose use can have extensive land use impacts -resources such as woodfuel, hydroelectric power, and geothermal energy -- the overwhelming influence of
site-specific factors (the local climate and ecology, land use patterns) render the use of generalized models
nearly impossible, if not downright misleading. The danger of biasing energy choices towards those
options whose environmental impacts are most difficult to assess or quantify -- “confusing the countable
with the things that count” -- must be avoided.
Developing Loadings Inventories and Projections for the Energy Sector
115
At the same time, increasing quantification, even monetization, of environmental externalities is
proceeding at a rapid pace. In the U.S., 29 states have acted to incorporate environmental externality costs
in electric sector planning.103 Internalizing environmental costs has been termed "the wave of the future"
internationally as well, with 85 pollution taxes already in place by 1989 in OECD countries (Ottinger,
1991, p. 190). So-called market-based initiatives, are rapidly spreading worldwide. Other options for
incorporating environmental externalities -- including solely qualitative assessment,
ranking/weighting/matrix schemes, and strict emission target approaches -- are also possible.
The Costa Rica study used the set of values for air pollutants emissions adopted by in states of
Massachusetts and Nevada, and shown in Table 5.4 below. This valuation was based on previous work by
Tellus Institute, using a "regulators revealed preferences" approach that is gaining increasing use in the
U.S.104 This approach uses the costs of existing and proposed environmental regulations as a proxy for the
value society implicitly or explicitly places on environmental impacts, and assumes that regulators have
made a reasonable assessment of the regulation's costs and benefits to society. For example, the SO2 cost
represents scrubbing technology required by regulation; the TSP cost represents baghouse technology; and
the CO costs represent the use of oxygenated fuels.
Table 5.4:
Air Pollutant Externality Values
Pollutant
SO2
NOx
CO
TSP
VOC
Value
(1990$/tonne)
$1700
$7500
$1000
$4600
$6100
CO2 (as
C)
$90
CH4
N2O
$250
$4600
In computing the air pollutant emissions from energy sector activities, the Costa Rica study used
different emission factors for its correspondingly different (relative to the US) mix of energy-using and transforming technologies, but the air pollutant externality values used were the same as noted above.
These values were not, however, used for resource selection, but only to produce indicative comparisons
with the direct market costs of the scenarios considered. While, ideally, the values (and methods used to
derive them) would be reassessed given the Costa Rican environmental situation, legislation, and priorities,
the application of the U.S.-based values does give an idea of what some of the environmental costs might
be, if emission regulations and control cost options were similar to those currently prevailing in the United
States.
103 Of these, 19 states have issued orders or passed legislation requiring utilities to include these costs in planning or new
capacity bidding processes.
104 For a review of this and other approaches see UCS et al., 1992, pp.37-39; Bernow, Biewald, and Marron, 1991; Chernick
and Caverhill, 1991; Pearce and Markandya, 1989; and, R. Ottinger, et al., 1990.
116
A Guide to Environmental Analysis For Energy Planners
Extending the Analysis from Emissions to Damage
117
6. Extending the Analysis from Emissions to Damage
6.1 Introduction
Once an LEAP/EDB analysis is complete, the typical result is a listing of pollutant emissions
and/or specific direct impacts per year. This type of information is often referred to as a loadings or
emission inventory, which can be a desirable end point of an analysis. Often, however, you may wish to go
beyond such an inventory to estimate the ultimate environmental damages associated with a particular
energy activities.
Over the past two decades, environmental agencies and researchers have devoted considerable
effort to developing models that have improved our ability to predict environmental damage to humans,
crops, materials, and ecosystems. Damage assessment can be either a relatively simple or exceedingly
difficult undertaking, depending on the complexity and uncertainty of the problem at hand. For example,
assessing the damages from greenhouse gas emissions presents an enormous scientific challenge, involving
the use of sophisticated computer models and innovative scientific research methods. Other impacts, such
as the impacts of air pollution on agricultural crops, are better understood and simpler to model.
Due the inherent difficulties and complexities of damage assessment, we have limited the coverage
of EDB to loadings and to direct impacts on health and safety, i.e. those that occur at the site of energy use
or production, rather than the indirect impacts that occur off-site and later in time, due to a variety of
possible pathways between loadings and damages. The many possible and often uncertain linkages
between loadings and damages generally defy simple linear relationships. In other words, “damage factors”
akin to the emission factors in EDB would not be appropriate. At the same time, more sophisticated air,
water, and soil models require considerable additional expertise and judgment in their application and are
often site-specific; given that LEAP/EDB users are largely energy analysts rather than environmental
analysts, we have not, as yet, included such models in the LEAP/EDB framework. The detailed extent of
data requirements and many factors influencing the choice of specific impact models for any situation
renders full damage assessment a difficult, if not impossible, proposition for LEAP/EDB or any other tool
of general applicability.
Some of the descriptions of pollutant impact models provided below will help to give you a feel for
the large amount of information that can be required to estimate final environmental damages of energy
sector activities. Air pollution impact models, for example, require data on the daily or monthly
distribution of emissions by spatial location, weather conditions at the time of the emissions, regional
topography, the location of receptors (including people, crops, and sensitive ecosystems), and the acute and
chronic response of these receptors to pollutant concentrations. These data and relationships can be highly
site-specific, and it can be difficult to attribute damages to the energy sector, which can be but one of many
sources of environmental stress.
In this section, we thus go beyond the scope of the LEAP/EDB framework, and provide some
background on available techniques and resources for estimating the eventual consequences of current and
projected environmental loadings. We begin by reviewing the steps in damage assessment, stopping short
of the ethically and methodologically challenging area of damage valuation.105 We then describe steps
105 For more discussion on methods for damage valuation, see the related SEI-B report Incorporating Environmental Concerns
in Energy Decisions: A Guide for Energy Planners (Hill, Lazarus, Bernow, and Biewald, 1994).
118
A Guide to Environmental Analysis For Energy Planners
involved in modeling emission-impact pathways for a few typical energy-related environmental concerns.
We provide some examples of the types of models used for simulating the fate and transport of pollutants
and their impacts on human and natural systems. We conclude with a brief listing and description of key
resources for environmental modeling and damage assessment.
6.2 Steps of Analysis from Emission to Impacts
Figure 6.1 depicts the major steps in impact assessment for energy activities. The first two steps,
characterizing energy activities and estimating loadings, can be done with LEAP/EDB or other similar tools
and techniques. The third and fourth steps, modeling the fate and transport of pollutants and establishing
dose-response relationships are the key elements of damage assessment, and the focus of this chapter:
•
Transport and fate of pollutants. This step is appropriate for air, water, and soil emissions where
impacts can occur downwind or downstream from the source of pollution. The objective is to predict
ambient concentrations of pollutants, and the accumulation of toxic substances, as well as the exposure
of populations and ecosystems to the pollutants. This step often requires the use of sophisticated and
data-intensive spatial and temporal atmospheric chemistry and dispersion models, such as, in the case
of global warming, complex global circulation models.
•
Exposure-response (or “dose-response”) relationships. For example, what effect will exposures of
say 5 µg/m3-year of sulfur dioxide have on human health, crop viability, or forest health? These types
of relationships are most commonly determined by laboratory, epidemiological, and field ecological
research studies. Relatively well-defined dose-response relationships exist for some interactions (for
example, SOx concentration and respiratory illness, ozone concentration and crop damage), while many
remain poorly understood (such as climate change impacts on ecosystems and human activities). This
step yields actual damage estimates: deaths, health impacts, ecosystem losses, crop and material
damages, diminished aesthetics, etc.
Additional, more direct damage pathways do not generally require modeling analyses, and are
indicated by the dotted line in Figure 6.1. These impacts include population and community displacement,
visual impairment, audible noise pollution, land use and degradation, loss of habitat and biodiversity.
These impacts are often associated with the construction of major energy facilities such as high-voltage
transmission lines or surface coal mines, but can also be associated with their continued operation (audible
noise from transmission lines or land degradation from surface mining, for example). They also tend to be
among the most obvious and controversy-provoking environmental concerns created by large energy
facilities. For example, many large proposed hydroelectric dams, such as the Three Gorges Dam on the
Yangtze River in China, the Sardar Sardovar Dam in India, and proposed dams on the Bio-Bio River in
Chile, have aroused local and international concern because of displaced communities, loss of wild and
riparian habitat, and inundation of sites of natural beauty.
Extending the Analysis from Emissions to Damage
Figure 6.1:
Steps in Physical Damage Assessment
1) Characterize Energy
Project or Scenario
technology characteristics, fuel use, losses, etc.
2) Estimate Loadings
air, water, and soil emissions
solid and hazardous wastes
3) Model Transport and Fate
of Emissions
pollutant exposures to populations,
ecosystems, crops, etc.
4) Establish ExposureResponse Relationships
deaths, health impacts, crop losses,
forest damage, etc.
Physical
Damages
direct resource use/degradation (soil
loss, habitat destruction, land use,
etc.) and aesthetic losses (audible
noise,/visual impact, etc.)
119
120
A Guide to Environmental Analysis For Energy Planners
These types of impacts tend to require site-specific assessments, in contrast to the types of
modeling efforts described here. Environmental Impact Assessments (EIA), where required, are natural
sources of this type of impact information. In only a few cases, such as for noise, EMF, and land use
impacts of electric transmission as discussed in Box 6.1, can generalized relationships be applied, and even
then local assessment would be far superior.
Box 6.1: The Environmental Impacts of High Voltage Electric Transmission Lines
(Based on Knoepfel, Bernow, and Lazarus, 1994)
In many countries, siting high-voltage transmission lines is becoming increasingly difficult. Local
resistance to the lines usually involves concern about the perceived impact of both the line itself and the
right of way (ROW) through which it runs. Local residents worry that a power transmission line will
change the area's visual aesthetics. They also fear the impacts of the ROW, in terms of possible soil
erosion and potential impacts on wetlands and wildlife. Finally, the public's perception of electric and
magnetic fields (EMF) raises further concerns that should be considered. In the U.S., environmental and
land use concerns are, together with the technical and economic assessment of system need, the most
important criteria applied in transmission line siting and certification throughout the U.S.
The environmental impacts of electric power lines can occur in ecosystems both at the local and at the
regional/global level. Typical local effects are related to the impacts on soils, local hydrology, flora and
fauna caused by construction processes and management of the right-of-way (ROW)7. Impacts on the
aesthetic quality of the landscape are also of a local nature. Regional/global effects arise from air
pollutants emitted at the stages of construction, production of materials, additional generation to
compensate electric losses, maintenance and decommissioning.
Knoepfel (1994) has developed a framework for classifying these impacts, as illustrated in the table
below, with some illustrative estimates of impacts typical for 345kV lines in the U.S. Such values,
however, must be used with caution, because the precise nature of the proposed right of way and
surrounding land use will have an overriding impact.
Table 6.1:
Environmental and health impacts of 345 kV AC transmission lines
(per kWh and 1000 km length).
Impact Category
Unit of Measurement
Rural Lines
Natural habitat impingement
0.001*m2
0.0012
2
Land depreciation
m *year
0.037
Audible noise impact
pers*hrs
0
(potential) Electric field impact
pers*hrs
0
(potential) Magnetic field impact
pers*hrs
0
Impact from air emissions
$
0.007
Air emissions impacts assume coal generation and monetary valuation.
Urban Lines
0
0.001
3.6
0
4.9
0.007
6.2.1 Examples Of Emission-To-Impact Pathways For Some Common Pollutants
The following examples illustrate some of the factors you will need to consider in translating
physical emissions of pollutants from energy-sector activities to estimates of the environmental damage.
The four case below are but a few of the many possible pathways between loadings and damages that
might be relevant in your region of concern.
Extending the Analysis from Emissions to Damage
121
Pathway Between Sulfur Oxide Emissions and Lung Disease
Sulfur oxide (SOx) emissions can result from many energy-sector activities, perhaps most notably
from the combustion of coal in domestic, commercial, industrial, or utility stoves, furnaces, and boilers.
Chronic (long-term) exposure to SOx emissions can lead to or contribute to lung diseases. Table 6.2
shows one pathway between emission and impact for SOx and lung disease, and lists some of the additional
data that you would need to gather in order to estimate impacts based on emissions.
Table 6.2:
Evaluation of the Respiratory Impacts of Sulfur Oxide Emissions
Steps in Evaluation Pathway
1. Emissions of sulfur oxides by energy
sector activities
2. Dilution, transport, and
transformation of SOx in the
atmosphere
3. Calculation of average and extreme
ambient concentrations of SOx
4. Determination of exposure of local
populations to SOx concentrations.
5. Estimate of number of additional or
aggravated cases of lung disease.
Data Needed For Estimation Of Impact
Sources of fuel combustion, fuel characteristics (e.g. sulfur
content), combustion and emission control technologies used,
emission coefficients (LEAP/EDB), and current and projected
energy-use activities. Modeling may require emissions data
on a daily or monthly basis.
Prevailing average and extreme weather conditions:
temperature on the ground and in the lower atmosphere,
humidity, wind, precipitation patterns, and local topography.
Presence or absence of other chemical species (such as dust,
salts) and rates of chemical reactions.
Output of steps 1 and 2.
Overlay of population distribution data, including identification
of sensitive groups (e.g. elderly and asthmatic) and SOx
concentration data (step 3),
Dose-response relationship between ambient exposure and
disease by class of exposed individual. There may be
different calculations for additional cases of lung disease
caused by chronic vs. acute exposure.
Pathway Between Carbon Dioxide Emissions and Economic Damage Due to Sea-Level Rise
Carbon dioxide emissions from combustion of fossil fuels and from changes in land use are
believed to be the major contributors to global warming. The resulting partial melting of the polar ice caps
and glaciers and thermal expansion of the oceans would increase the average level of the oceans, with
potentially devastating effects to many coastal communities. Translating emissions of CO2 to economic
impacts requires analysis of a cause-and-effect pathway like that shown in Table 6.3.
122
A Guide to Environmental Analysis For Energy Planners
Table 6.3:
Evaluation of the Sea-Level-Rise Impacts of Carbon Dioxide Emissions
Steps in Evaluation Pathway
1. Emissions of CO2 by global energy
sector activities, land-use changes, and
other anthropogenic sources
2. Estimated range of possible
temperature rise
3. Calculation of sea level rise resulting
from a particular temperature increase
4. Estimate of human and natural
activities and assets at risk from sea
level rise
Data Needed For Estimation Of Impact
Sources of fuel combustion, fuel characteristics (including
carbon content), combustion and emission control
technologies used, emission coefficients (LEAP/EDB), and
current and projected energy-use activities.
Estimates of the fate of CO2 (absorption by ocean water and
growing biomass), emissions of other important greenhouse
gases, and various assumptions regarding the global climate
system, including the radiative balance of the earth, weather
patterns, cloud cover, and the modulating impact of the
oceans upon climate. These data are then used in "Global
Circulation Models".
Data on the size and reflectivity of ice caps and glaciers,
thermal ocean expansion, and feedbacks between rising
oceans, temperatures and melting ice caps.
Inventory of population, property, and ecosystems at risk from
sea level rise, probably response to rise.
Pathway Between Nitrogen Oxide Emissions and Impacts on Lake Ecosystems through
Acidification
Nitrogen oxide (NOx) emissions from combustion of fuels have been implicated in the formation of
"Acid Rain", which can acidify lakes to the detriment of fisheries and aquatic ecosystems. The steps shown
in Table 6.4, below, are one route by which the linkage between NOx emissions and lake ecosystem damage
can be traced.
Table 6.4:
Evaluation of the Lake Ecosystem Impacts of Nitrogen Oxide Emissions
Steps in Evaluation Pathway
1. Estimate of NOx emissions by
energy sector activities
2. Analysis of fate and transport of
NOx emissions in the atmosphere
3. Calculation of the extent and timing
of acid precipitation in watershed
4. Estimate of the degree to which a
lake and its surrounding soil is acidified
5. Estimate of ecosystem damage due
to acidification
Data Needed For Estimation Of Impact
Sources of fuel combustion, fuel characteristics, combustion
and emission control technologies used, emission coefficients
(LEAP/EDB), and current and projected energy-use activities
Prevailing weather patterns, including wind regimes,
precipitation patterns, and temperatures. Concentrations of
other constituents of the atmosphere, estimates of the rates
and parameters of chemical reactions in the atmosphere
Size of lake's watershed, amount of precipitation falling and
form of precipitation, timing of snow melt, degree to which
areas receives dry precipitation of acidic species
Type of soil around the lake, chemical buffering capacity of
the lake and watershed soils, extent of run-off, timing of snow
melt, hydraulic properties of the watershed (such as ratio of
lake volume to water flow through lake)
Types of organisms in the lake and watershed ecosystems,
population sizes and relationships (e.g. food chains), degree
to which other damaging chemicals (including aluminum) are
mobilized by acidification, susceptibility of different lake and
watershed organisms to acidic conditions (or mobilized toxins)
6.3 Types of Models and Approaches for Impact Assessment
Extending the Analysis from Emissions to Damage
123
Once you have completed your inventory of emissions and direct impacts from energy-sector
activities, and have determined likely pathways leading from emissions to environmental impacts (as in the
previous section), the next task would be to obtain or derive a series of models to estimate the magnitude of
the damage. Considerations in choosing among these models will include:
•
•
•
•
The type of results desired (ambient concentration by location, biological uptake of toxic
contaminants, etc.);
The availability of required model data;
The technical expertise and computing resources available to specify, calibrate, and run a
model and to interpret model results; and,
The accuracy and precision of results, which will depend on the application of the results (for
example, to inform a policy decision or to assist in regulation and monitoring).
In this section we provide thumbnail sketches of the general types of models that are available to
help estimate environmental impacts, and present brief descriptions of some of the available models that
have been developed for particular classes of impact assessments. Ranging from simple to very complex
computational approaches, we discuss the following five types of models below:
•
•
•
•
•
Stock-flow models
Transport/plume/dispersion/deposition models
Atmospheric chemistry models
General circulation/climate models
Dose-response models
6.3.1 Stock-Flow Models
Stock-flow models can provide the simplest approach to estimating pollutant concentration and
accumulation. These models characterize specific volumes or areas -- urban airsheds, lakes, watershed,
etc. -- as well-mixed “boxes”, with inflows and outflows of air, water, pollutants and/or other substances.
These models are generally most applicable to estimating the concentrations of pollutants in receiving water
bodies, such as lakes and rivers, but they can be also applied to other environmental media where relatively
even mixing of the pollutant with the “box” can be assumed.
The simplest forms of these models are called "steady-state" models, and are used to estimate the
conditions of a system--for example a lake and its tributary watershed--that has reached equilibrium with
respect to the concentration of a pollutant (that is, a lake in which the concentration of a pollutant is no
longer changing). Box 6.2 below provides an simple of a simple “steady-state” stock-flow model for
evaluating pollutant concentrations.
124
A Guide to Environmental Analysis For Energy Planners
BOX 6.2:
A Simple Stock-Flow Model for Lake Pollution
Situation: A geothermal power plant releases brine (very salty water) into a nearby mountain lake. On an
average day, the plant releases brine containing 6000 tonnes of salt (Sin). You can assume that the lake is wellmixed, that the water coming into the lake (except for that released by the plant) is fresh water, and that water
leaves the lake via an outflow river at a rate of 10,000 m3/day (Fw). You want to calculate the average
concentration of salt in the lake water, and to evaluate whether this salinity level will harm the lake’s plants and
organisms.
Salt inflow
Sin = 6000t/day
Water outflow
Fw = 10,000 m3/day
MOUNTAIN LAKE
Solution: Because we have assumed that the lake is well-mixed, he concentration of salt in the water exiting the
lake should be the same as the average concentration is the whole lake itself. This is the notion of “steady-state”
conditions; initial conditions would be “dynamic” as the concentration in the unpolluted lake rises. Further, at
steady-state, the amount of salt entering the lake from the power plant must be the same as the amount of water
exiting the lake in the outflowing river. This means that we can determine the concentration of salt in the lake by
calculating the concentration (C) in the lake outflow: C = Sin/ Fw, or 6000 tonnes/day divided by 10,000 m3/day.
The time units (days) cancel, and we are left with a resulting concentration of 0.06 tonnes per m3, or 60 grams of
salt per liter. To put this value into perspective, the salinity of the ocean is (on average) about 35 grams per liter.
The salt burden provided by the power plant would thus exceed a marine environment, with likely serious damage
to the existing freshwater ecosystem.
Stock-and-Flow or Box models can also be used to estimate the properties of a dynamic system,
such as the modeling of changes in the concentration of a pollutant over time. Harte (1985) provides a
discussion of some of the uses of these types of models, including a variety of numerical examples.106
6.3.2 Transport/Plume/Dispersion/Deposition Models
"Transport", "Plume" or "Dispersion" models can be used to estimate the concentrations of air or
water pollutants at a distance from the points where the pollutant is emitted. The results of these models
can be used to determine compliance with air or water quality standards or used to infer human health
effects or other environmental impacts, through the use of exposure-response models (see below).
These models, generally, use a combination of mathematical relationships107, and require detailed
data on wind (or water flow) patterns, terrain, and precipitation, to approximate the dispersion of pollutants
over time, in a receiving airshed or body of water. These models range in complexity from those simple
enough to be calculated on a programmable hand calculator or personal computer to those requiring main-
106Harte, J. (1985). See for example Sections A and D of Chapter II.
107These include "Gaussian", "Lagrangian" and "Eulerian" algorithms used to calculate, in a probabalistic manner, how
concentrations of pollutants will vary in time and space as they spread out from their sources
Extending the Analysis from Emissions to Damage
125
frame or supercomputers. The types of models available can be grouped into several overlapping
categories of applicability:
•
•
•
•
Short-range models used for receptor areas within about 50 kilometers of a source of air
pollution;
Long-range or regional models designed, as their name implies, to estimate the concentrations
or deposition of pollutants over a wider area and over a longer time-frame;
Point-source models, which estimate pollutant concentrations due to emissions from a major
emitter, such as a power plant or a large industrial facility; and,
Area-source models, which look at emissions from a combination of point sources, often too
small, such as automobiles or residential stoves and furnaces, to be given a specific location,
and thus considered “area sources”.
Economopolous (1993)108 presents a pair models for use in rapid evaluation of the impacts of air
pollution, along with all of the equations, definitions of site-specific data requirements and non-site-specific
technical data needed to run them. The first model is a "Short Term Critical Impact Analysis" tool
designed to evaluate whether concentrations of a pollutant from a point source exceed critical levels for
short-term (e.g. one-hour) exposure. The second model is for "Long Term (Seasonal or Annual) Impact
Analysis", and is used, as the name implies, to estimate the average values of pollutant concentrations, this
time from point or area sources, in a given receptor area.
Another excellent source for those seeking information on the availability and applicability of a
variety of air quality models is the United States Environmental Protection Agency document Guideline on
Air Quality Models109. This extensive document provides a review of the models available for specific
types of applications, discussions of the general requirements, considerations, data needs, and uncertainties
in air quality modeling. It also provides lists describing both a) the air quality models preferred by the
EPA, and b) alternative air quality models to the preferred lists. These lists are included as Appendix C to
this manual--along with the table of contents from the EPA document--to illustrate the large number of
available models and the important issues to consider in their application.110
One use of long-range transport and deposition models is in the modeling of acid precipitation.
The goal of these models is to estimate the location and strength of acid precipitation (acidity in rain and
snow, as well as from dry deposition) caused by air pollutant emissions. A major source of the acid
pollutant emissions (for example, the United Kingdom) may be hundreds of kilometers away from the
region of deposition and ultimate impact (such as Scandinavia). Several models have been developed to
help estimate the impacts of acid gas emissions (primarily SOx and NOx).
108Economopolus (1993).
109United States Environmental Protection Agency (USEPA), Guideline on Air Quality Models. USEPA Office of Air and
Radiation, Office of Air Quality Planning and Standards, Research Triangle Park, North Carolina, USA. Report number EPA450/2-78-027R, originally published July 1986. Portions of the report were revised with "Supplement A" (July 1987) and
"Supplement B" (February, 1993). This report, and many others touching on air quality emissions inventories, emissions
controls, and emission modelling, are also available through the USEPA computer bulletin board service, which can be reached
(by those with a computer and modem) by dialing (in the United States) 919-541-5742.
110As an example, H.P. Baars, K.D. van den Hout, and C. Huygen describe a tool designed for use in evaluating the extent and
impacts of local air pollution in the Netherlands in their paper "Air Pollution Information System Tool for Desk Top Air
Pollution Management on a Local Scale", published in Environmental Models: Emissions and Consequences, Risø
International Conference, 22-25 May, 1989, edited by J. Fenhann, H. Larsen, and G.A. Mackenzie. Published by Elsevier
Science Publishers, Amsterdam, The Netherlands, 1990.
126
A Guide to Environmental Analysis For Energy Planners
Two models consider not only the emission, transport, and deposition of acid pollutants, but the
sensitivity of local ecosystems and, using postulated dose-response relationships, the impact on affected
areas. These models, CASM111 and RAINS112 were both developed in Europe, at the Stockholm
Environment Institute and the International Institute for Applied Systems Analysis, respectively, but have
recently been extended for other regions including South Asia, where acid precipitation is a growing
concern. They also contain optimization capabilities that enable the user to evaluate a least-cost, leastdamage acid rain abatement strategy.
6.3.3 Atmospheric Chemistry Models
Some air pollutants, after they are emitted, can be involved in important chemical changes in the
atmosphere. These changes can render a pollutant less or more hazardous to the environment. Many of
the models discussed above have atmospheric chemistry components, and most atmospheric chemistry
models will have some pollutant transport elements.
Tropospheric ozone models are a prime example of atmospheric chemistry models. Ozone can be a
major urban air pollutant, associated with photochemical smog, but is not directly emitted from human
sources in significant amounts. Instead, it is produced by the atmospheric reaction of nitrogen oxides and
volatile organic compounds in presence of sunlight. Several ozone models are available, but they are
particularly complex and quite consumptive of computing and data resources.113 Nonetheless, some
efforts are underway to produce models that are more easily calibrated (tested with data from monitoring
stations) and calculated, and thus may be more practical for use in developing-country settings.114
6.3.4 General Circulation/Climate Models
General circulation models (GCMs) are used, in part, to estimate the long-term effect on the earth's
climate of changes in the atmosphere, including the changes in concentrations of greenhouse gases. Several
such models currently running on large mainframe computers at different centers around the world.115
They operate at different levels of spatial aggregation, that is, they break the surface of the earth into
"cells" of different sizes -- and the atmosphere into different numbers of "layers" -- for modeling purposes.
Some of the many elements of the climate system that need to be modeled include116:
111Stockholm Environment Institute, 1991. An Outline of the Stockholm Environment Insitute’s Coordinated Abatement
Strategy Model (CASM). SEI, Stockholm.
112See for example Alcamo et al (1987), "Acidification in Europe: A simulation model for Evaluating Control Strategies",
Ambio, Vol. 16 number 5, pages 232 - 245.
113 See discussion of ozone modeling in Rowe, R. Lang, C. et al. (RCG/Hagler, Bailly, Inc.1993), New York Environmental
Externalites Study: Task 2, Externalities Screening and Recommendations, prepared by RCG/Hagler, Bailly, Inc.for the Empire
State Electric Energy Research Corporation, New York.
114See for example G.M.Johnson, S.M. Quigley, and J.G. Smith, "Management of Photochemical Smog Using the Airtrak
Approach", in 10th International Conference of the Clean Air Society of Australia and New Zealand, Aukland, N.Z., March
1990, pp. 209 to 214, and C.L. Blanchard, P.M. Roth, and H.E.Jeffries, "Spatial Mapping of Preferred Strategies for Reducing
Ambient Ozone Concentrations Nationwide", Presented at the 86th Annual Meeting and Exhibition of the Air and Waste
Management Association, June 13-18, 1993, Denver, Colorado, USA.
115Laboratories running GCMs include UKMO (United Kingdom Meteorological Office), GFDL (Geophysical Fluid Dynamics
Laboratory, Princeton, USA), CCC (Canadian Climate Center), MRI (Meteorological Research Institute, Japan), NCAR
(National Center for Atmospheric Research, Boulder, Colorado, USA), and GISS (Goddard Institute of Space Studies, New
York, New York, USA).
116Intergovernmental Panel on Climate Change (IPCC, 1990), Scientific Assessment of Climate Change, IPCC Working
Group I Report, J.T. Houghton, Chairman. Chapter 3, "Processes and Modelling" authored by U. Cubasch and R. Cess. IPCC
Extending the Analysis from Emissions to Damage
•
•
•
•
•
•
•
127
The atmosphere
The oceans
The cryosphere (ice and snow cover, especially at the poles)
The biosphere (trees, and other vegetation, soil, etc.)
The geosphere (for example, how the land is involved in cycles of evaporation and
precipitation of water)
Different time scales of climate processes
Radiative feedback mechanisms
In general, global circulation models must be run on the fastest supercomputers available, and are
thus not practically available for use by most energy planners. Simpler models of specific climate
processes and elements of the climate system do exist, however. (see IPCC, 1990) For example, the
Atmospheric Stabilization Framework (ASF) used by US EPA in its widely distributed report, Policy
Options for Stabilizing Global Climate, is available in PC form.117 The STUGE (Sea level and
Temperature change Under the Greenhouse Effect) model is another simplified PC-based model that can be
used to estimate the climatic implications of greenhouse gas emission scenarios at a global level.118
6.3.5 Dose-Response Models
Dose-response models represent a class of tools used to estimate the “response” of an individual,
group of individuals, or ecological system to a “dose” of pollution. Different dose-response relationships
are needed for different response pathways.
In their simplest forms, these models are linear or non-linear relationships in which the impact of a
pollutant--such as the fraction of a population (of plants, fish, humans, or any other organism that will be
affected (killed, injured, or diseased)--is expressed as a function of the dose of the pollutant to which the
organism is, on average, exposed. The dose may be expressed in micrograms of pollutant absorbed by an
organism per unit body weight (or surface area), a length of time that an individual is exposed to a
particular concentration of a gas in the atmosphere, or (as in electro-magnetic radiation and radioactive
materials) an amount of energy absorbed by the body of an animal or human. Linear dose response
relationships imply that the impacts of a dose of pollutant will increase linearly as the dose is increased.
“Threshold” dose response relationships are non-linear: no impact is felt until a pollutant dose reaches a
threshold value. Such relationships are intended to represent the hypothesis that organisms can tolerate
small doses with no adverse effects, whereas above a threshold value, negative impacts begin.
More complex dose-response models may take into account the interactions of different types of
plants and animals living together in an ecological community (e.g. the concentration of a pollutant a food
chain), the conversion of a pollutant into a less (or more) dangerous substance through biological (like the
Secretariat, Geneva, Switzerland. See also Chapter 4 from the same volume: "Validation of Climate Models", authored by
W.L. Gates, P.R. Rowntree, and Q.-C. Zeng. The IPCC has prepared several publications updating this Assessment (IPCC,
1992; IPCC, 1994).
117United States Environmental Protection Agency (USEPA, 1990c), Policy Options for Stabilizing Global Climate: Report to
Congress (Main Report and Technical Appendices). USEPA Reports #s 21P-2003.1 and 21P-2003.3, USEPA Office of
Policy, Planning, and Evaluation, Washington, D.C. USA.
118Wigley, T., Holt, T., Raper, S. 1991. STUGE, an Interactive Greenhouse Model, Climate Research Unit, University of East
Anglia, Norwich, U.K.
128
A Guide to Environmental Analysis For Energy Planners
detoxification or toxification of a compound in the body) or physical processes (for example, through
chemical reactions in the atmosphere), or the effect of a release of a point-source pollutant on a population
that is not homogeneous with respect to exposure and/or susceptibility to the source of the pollutant. This
last category of relationships might, for example, include evaluating the relationship between emissions of a
toxic substance from a power plant, and cancers of a particular type in the population of nearby residents;
this is the province of the field of epidemiology. If a pollutant persists in the environment, calculation of
its ultimate effect may require integration of its impacts over the time during which it is biologically active
(that is, has an effect on the environment). In many cases using dose response models may involve
comparing known doses to existing empirical dose-response data119.
6.4 Some Simplified Indices And Selected Standards
6.4.1 Global Warming Potentials
Simpler models and relationships, however, have been used to estimate, for example, the specific
"radiative forcing" (change in the global heat balance) attributable to changes in the concentrations of
greenhouse gasses in the atmosphere120. The results of some of these models, plus some results of
atmospheric chemistry models, have contributed to sets of relationships that allow the relative climatechanging ability of emissions of different greenhouse gasses to be compared. These relationships are
called Global Warming Potentials, or GWPs. GWPs can be (with care) applied directly to estimates of
emissions of the different species of greenhouse gasses to produce an overall estimate of warming potential,
often expressed in kilograms of CO2 or kilograms of carbon, for emissions from a given country or region
(for example) per unit time. Table 6.5, below, provides some of the estimates of Global Warming
Potential published by the Intergovernmental Panel on Climate Change, or IPCC.
Table 6.5
Global Warming Potentials Relative to CO2 Reference
(100 year time Horizon; Selected Compounds; Source: IPCC, 1994)
Species
Carbon Dioxide
Methane
Nitrous Oxide
CFC-11
CFC-12
CFC-13
CFC-113
CFC-114
CFC-115
HCFC-22
HCFC-123
Carbon Tetrachloride
HFC-134a
Chemical Formula
CO2
CH4
N2O
CFCl3
CF2Cl2
CClF3
C2F3Cl3
C2F4Cl2
C2F5Cl
CF2HCl
C2F3HCl2
CHCl3
CH2F2CF3
Lifetime (yrs)
50 - 200
12-17 (adjustment time)
120
45 - 55
102
640
85
300
1700
13.3
1.4
42
14
GWP
1
24.5
320
4000
8500
11700
5000
9300
9300
1700
93
1400
1300
119These type of data are available from many sources. One compendium where one can find a variety of data on the human
health effects of a number of different pollutants is Doull, J.D, C.D. Klaassen, and M.O. Amdur, editors, Casarett and Doull's
Toxicology, Second Edition, 1980, Macmillan Publishing Co., N.Y., N.Y., USA, pages 317 - 319.
120See for example Lashof, D.A., and D.R. Ahuja, Nature, 5 April 1990, pp. 529-531.
Extending the Analysis from Emissions to Damage
129
6.4.2 Air Quality Indices
In some nations and local areas, indices of air quality are used to translate the sometimes confusing
jargon of hourly and daily concentrations for specific pollutants into a general indicator of the health risks
of outside air on a given day. When an index exceeds a certain value, activities such are playing or
working outside for extended periods are discouraged, and residents are urged to take special precautions.
6.4.3 WHO Environmental Standards
The World Health Organization publishes sets of guidelines for air pollutant concentrations in
inhabited areas. When local conditions exceed these standards--which are specified as maximum average
concentrations over various periods of time (including hourly, daily, and annual averages) of specific
pollutants such as particulate matter, nitrogen dioxide, ozone, and others--it is an indicator of poor or
declining air quality. A summary of these air quality guidelines (from WHO/UNEP 1994) is provided as
Table 6.6121.
Table 6.6
Summary of WHO Air Quality Guidelines (Source: WHO/UNEP, 1994)
Pollutant
Sulfur Dioxide
Carbon Monoxide
Nitrogen Dioxide
Ozone
Suspended Particulate Matter
Black Smoke
Total Suspended Particulates
Time-weighted Average
500
350
100 - 150 b
40 - 60 b
30
10
400
150
150 - 200
100 - 120
Unitsa
µg/m3
µg/m3
µg/m3
µg/m3
mg/m3
mg/m3
µg/m3
µg/m3
µg/m3
µg/m3
Averaging Time
10 minutes
1 hour
24 hours
1 year
1 hour
8 hours
1 hour
24 hours
1 hour
8 hours
100 - 150 b
40 - 60 b
150 - 230 b
60 - 90 b
70 b
0.5 - 1
µg/m3
µg/m3
µg/m3
µg/m3
µg/m3
µg/m3
24 hours
1 year
24 hours
1 year
24 hours
1 year
Thoracic Particles (PM10)
Lead
Notes:
a
Milligrams (mg/m3) or micrograms (µg/m3) of pollutant per cubic meter of air.
b
Guideline values for combined exposure to sulfur dioxide and suspended particulate matter (they may not
apply to situations where only one of the components is present).
121 Note that these guidelines are contained (as referenced in WHO/UNEP, 1994) in a series of 1977 through 1979 WHO
“Environmental Health Criteria” reports (numbers 3, 4, 6, 8, and 13), each of which covers particular classes of pollutants.
130
A Guide to Environmental Analysis For Energy Planners
6.5 Suggested Resources for Environmental Modeling
•
The US EPA maintains a “Clearinghouse” of tools for modeling of air quality. Information on the
attributes of a number of models is available from the USEPA Office of Air Quality Planning and
Standards in the Office of Air and Radiation, USEPA, Research Triangle Park, North Carolina, USA.
Many computer-based air quality modeling tools are also available from this source, as well as
documentation on how (and how not) to use them. Some of the models and information is available
through a computerized “bulletin board” called “SCRAM” that interested parties can reach via modem.
Please see Appendix B for further USEPA information on air quality models.
•
The World Health Organization’s Assessment of Sources of Air, Water, and Land Pollution: A Guide
to Rapid Source Inventory Techniques and their Use in Formulating Environmental Control
Strategies. (Economopolous, 1993). This two-volume manual provides several simple models and
methods specifically designed for planners with limited resources, and is available in several languages.
•
The report Externalities Screening and Recommendations, prepared for the New York State
Environmental Externalities Cost Study by a team headed by RCG/Hagler, Bailly, Inc. (1993),
includes summaries of air quality models and of the impacts of air and water pollutants, solid waste
disposal, and other environmental impacts of energy systems.
•
The book, Consider a Spherical Cow: A Course in Environmental Problem Solving, by John Harte of
the University of California at Berkeley (Harte, 1985), contains a wealth of insights on the basic
approaches for modeling environmental processes.
The series of reports prepared under the USEPA’s “Atmospheric Stabilization Framework” effort (see
USEPA, 1990c) and entitled Policy Options For Stabilizing Global Climate includes the review and
application of a number of different models related to climate change (see the Technical Appendix to the
Policy Options.. reports). Some of these models have, in the past, been available from the USEPA on
computer diskettes.
References
131
7. References
A.O. Adegbulugbe (1992), "Energy-Environmental Issues in Nigeria", paper presented at the International
Energy Workshop, Harvard University, Cambridge, MA, June 1992
Alcamo et al (1987), "Acidification in Europe: A simulation model for Evaluating Control Strategies".
Ambio, Vol. 16 number 5, pages 232 - 245.
Asian Development Bank (1991), Environmental Considerations in Energy Development. Energy and
Industry Department, World Bank, Washington D.C., USA. May 1991.
Baars, H.P., K.D. van den Hout, and C. Huygen (1990), "Air Pollution Information System Tool for Desk
Top Air Pollution Management on a Local Scale". In Environmental Models: Emissions and
Consequences, Risø International Conference, 22-25 May, 1989, edited by J. Fenhann, H. Larsen, and
G.A. Mackenzie. Published by Elsevier Science Publishers, Amsterdam, The Netherlands.
Bernow, S., B. Biewald, and D. Marron (1991), "Environmental Externalities Measurement:
Quantification, Valuation, and Monetization". In External Environmental Costs of Electric Power,
Hohmeyer, O., Ottinger, R., eds. Springer-Verlag, Berlin, 1991.
Blanchard, C.L., P.M. Roth, and H.E.Jeffries, "Spatial Mapping of Preferred Strategies for Reducing
Ambient Ozone Concentrations Nationwide", Presented at the 86th Annual Meeting and Exhibition of the
Air and Waste Management Association, June 13-18, 1993, Denver, Colorado, USA.
Bose, R.K., and V.Srinivasachary (1992), Policies to Reduce Energy Use and Environmental Emissions
in the Transport Sector: A Case of Delhi City, Tata Energy Research Institute, New Delhi, 1992.
California Air Resources Board (1990). California Air Quality Data, 1990 Annual Report. California
Air Resources Board, Sacramento, California, USA.
California Air Resources Board (1991a), Methods for Assessing Area Source Emissions in California.
September, 1991, CARB, Sacramento, CA, USA.
State of California Air Resources Board (1991b), Identification of Volatile Organic Compound Species
Profiles, ARB Speciation Manual, Second Edition, Volume 1 of 2, August, 1991. CARB, Sacramento,
CA, USA.
Chernick, P., and E. Caverhill (1991), “Methods of Valuing Environmental Externalities”. The Electricity
Journal 4 (2), March, 1991.
Corinair (1992), Default Emission Factors Handbook. Corinair Inventory - Commission of the European
Community. Published by Commission of the European Community.
Davidson, O., and S. Karekezi (1991), An Energy Strategy for Environmentally-Sound Development in
Sub-Saharan Africa," African Energy Policy Research Network, September 1991.
132
A Guide to Environmental Analysis For Energy Planners
DeLuchi, M.A. (1991), Emissions of Greenhouse Gases from the Use of Transportation Fuels and
Electricity, Volumes 1 & 2. Center for Transportation Research, Argonne National Laboratory, Argonne,
IL, USA. Dated November 1991. Report number ANL/ESD/TM-22, Vol. 1 & 2.
Doull, J., C.D. Klassen, and M.O. Amdur (1980), Casarett and Doull’s Toxicology: The Basic Science of
Poisons. Macmillan Publishing Co., New York, N.Y., USA.
Economopoulos, A. P. (1993), Assessment of Sources of Air, Water, and Land Pollution: A Guide to
Rapid Source Inventory Techniques and their Use in Formulating Environmental Control Strategies.
World Health Organization, Geneva, Switzerland. Two part report; Part One: Rapid Inventory
Techniques in Environmental Pollution. Part 2: Approaches for Consideration in Formulating
Environmental Control Strategies. WHO/PEP/GETNET/93.1A & B.
Ellegard, A., and H. Egneus (1992). Health Effects of Charcoal and Woodfuel Use in Low-Income
Households in Lusaka, Zambia. Stockholm Environment Institute Report, ISBN 91-88116-48-4.
Ehrlich, P.R, A.H. Ehrlich, and J.P. Holdren (1977), ECOSCIENCE. W.H. Freeman and Co., San
Francisco, California, USA.
Faiz, A. (1991), "Automotive Emissions in Developing Countries - Relative Implications for Global
Warming, Acidification, and Urban Air Quality", In Conference on Transportation and Global Climate
Change, Pacific Grove, CA. August 1991.
Falloux, F., L.Talbot, and J. Larson, (1991) Progress and Next Steps for National Environmental Action
Plans in Africa, World Bank Africa Technical Department, June 1991.
Fontelle, J.P. (1990), "The CORINAIR Project - An EC Air Pollutant Inventory". In Environmental
Models: Emissions and Consequences, Risø International Conference, 22-25 May, 1989, edited by J.
Fenhann, H. Larsen, G.A. Mackenzie, and B. Rasmussen. Elsevier, Amsterdam, Oxford, New York, and
Tokyo.
Freedman, B. (1989), Environmental Ecology. Academic Press, San Diego California, USA.
Geller, H. (1991), Efficient Electricity Use: A Development Strategy For Brazil. American Council for
an Energy Efficient Economy, Washington, DC, USA, 1991.
Gipe, P. (1991), “Wind Energy Comes of Age: California and Denmark”, Energy Policy, Vol. 19, No. 8,
pp.756-67. October.
Harte, J. (1985), Consider a Spherical Cow: A Course in Environmental Problem Solving. William
Kaufman Inc., Los Altos, California, USA.
Hill, D., M. Lazarus, S. Bernow, and B. Biewald (1994), Incorporating Environmental Concerns in
Energy Decisions: A Guide for Energy Planners. SEI-B Report; SEI-B, Boston, MA, USA.
Holdren, J. P. (1990). "Energy in Transition", Scientific American, September, 1990.
Hollander, J.M. (Editor) (1992), The Energy-Environment Connection. Island Press, Washington, D.C.,
USA.
References
133
Hosier, D., and J. Boberg, (1993) "Charcoal Production and Environmental Degradation: Environmental
History, Selective Harvesting, and Post-Harvest Management", Energy Policy, Vol 21, No.5, May.
Instituto Costarricense de Electricidad (ICE, 1991), Sistema Nacional Interconectado, Resumen. Prospective
dated March 4, 1991.
IPCC (1990). Scientific Assessment of Climate Change, Intergovernmental Panel on Climate Change,
Working Group I, J.T. Houghton, Chairman. IPCC Secretariat, Geneva; June, 1990.
IPCC (1992). Scientific Assessment of Climate Change, 1992 Supplement, Intergovernmental Panel on
Climate Change, United Nations Environment Programme and the World Meteorological Organization.
IPCC (1994). Radiative Forcing of Climate Change, The 1994 Report of the Scientific Assessment
Working Group of the IPCC. Summary for Policymakers, Intergovernmental Panel on Climate Change,
United Nations Environment Programme and the World Meteorological Organization.
Intergovernmental Panel on Climate Change (IPCC, 1990), Methane Emissions and Opportunities for
Control. Published by the US Environmental Protection Agency, USEPA Report # 400/9-90/007.
IPCC/OECD (1993), Greenhouse Gas Inventory Workbook: IPCC Draft Guidelines for National
Greenhouse Gas Inventories. Prepared for the Intergovernmental Panel on Climate Change. Final Draft
Version, December, 1993. Volume 2 of 3 in the series.
Johansson, T., Kelly, H., Reddy, A., Williams, R. (1993), Renewable Energy: Sources for Fuels and
Electricity. Burnham, L. ed., Island Press, Washington, D.C., USA.
Johnson, G.M., S.M. Quigley, and J.G. Smith, "Management of Photochemical Smog Using the Airtrak
Approach". In 10th International Conference of the Clean Air Society of Australia and New Zealand,
Aukland, N.Z., March 1990, pp. 209 to 214.
Katsouros, M. H. (1992), "Oil Spills". Chapter 5 in The Energy-Environment Connection, J. M.
Hollander, ed., Island Press, Washington, D.C., USA; pp. 109-132.
Knoepfel, I. (1994). “Energy Transmission and Distribution Systems: Framework for Environmental
Impact Analysis in Integrated Resource Planning”, Tellus Institute Report #94-025, Boston.
Knoepfel, I., S. Bernow, and M. Lazarus (1994), "Environmental Impacts of Long Distance Energy
Transport." Proceedings of the ACEEE 1994 Summer Study Conference.
Latin American Energy Organization (OLADE, 1991), Energy-Economic Information System for Latin America
and the Caribbean (SIEE), March, 1991 version. Developed by OLADE with funding from the European
Economic Commission. Quito, Ecuador.
Leggett, J. (Editor) (1990), Global Warming, The Greenpeace Report. Oxford University Press, New
York, New York, USA. 554 pp.
Levine, J.S. (1992), “The Global Atmospheric Budget of Nitrous Oxide”. In 5th International Workshop
on Nitrous Oxide Emissions, Tsukba, Japan, July 1 - 3, 1992, organized by the National Institute for
134
A Guide to Environmental Analysis For Energy Planners
Resources and the Environment (Japan), Institut Françias du Pétrole, U.S. Environmental Protection
Agency, and The Society of Chemical Engineers, Japan. Pages KL-1-1 to KL-1-8.
Moreira, J., and A. Poole (1993). , "Abatement of Carbon Dioxide Emissions in Brazil". In The Global
Greenhouse Regime: Who Pays?, K.R. Smith and P. Hayes, P., eds. United Nations University Press,
New York, N.Y., and Earthscan Publications Ltd., London, UK.
Morrison, R.T, and R.N. Boyd (1973), Organic Chemistry. Third Edition, Allyn and Bacon, Inc., Boston,
MA, USA.
Murarka, Ishwar P. (1987). Solid Waste Disposal and Reuse in the United States, Volume II. CRC
Press, Boca Raton, Florida, USA.
OECD/IPCC (1991), Estimation of Greenhouse Gas Emissions and Sinks: Final Report from the OECD
Experts Meeting, 18-21 February 1991. Prepared for the Intergovernmental Panel on Climate Change.
August Revision, 1991.
Oldeman, L.R., V.W.P. van Engelen, and J. H. M. Pulles (1990), "The Extent of Human-Induced Soil
Degradation," Annex 5 of L. R. Oldeman, R. T. A. Hakkeling, and W. B. Sombroek, World Map of the
Status of Human Induced Soil Degradation: An Explanatory Note, rev. 2d. ed., International Soil
Reference and Information Centre, Wageningen, the Netherlands, 1990.
ORNL (1989). Estimates of CO2 Emissions from Fossil Fuel Burning and Cement Manufacturing.
Based on the United Nations Energy Statistics and the U.S. Bureau of Mines Cement Manufacturing
Data. G. Marland et al, Oak Ridge National Laboratory, May 1989. ORNL/CDIAC-25.
O'Keefe, P., P. Raskin, and S. Bernow (1984), Energy and Development in Kenya: Opportunities and
Constraints. Vol. 1, Energy, Environment, and Development in Africa, Beijer Institute, Stockholm, 1984.
Ottinger, R. et al (1990), Environmental Costs of Electricity. Oceana Publications, Inc., Dobbs Ferry,
NY, USA. September, 1990.
Ottinger, R. (1991), "Consideration of Environmental Externality Costs in Electric Utility Resource
Selections and Regulation". In Energy Efficiency and the Environment: Forging the Link, Vine, E. et al.,
eds. American Council for an Energy-Efficient Economy, Washington, DC, 1991.
Pasqualetti, M.J., and B.A. Muller (1984). “Land Requirements for the Solar and Coal Options”,
Geographical Journal, Vol.150, No.2, July.
Pearce, W., and A. Markandya (1989), Environmental Policy Benefits: Monetary Valuation. OECD,
Paris, France.
Philips, M. (1991), The Least Cost Energy Path for Developing Countries: Energy Efficient Investments
for the Multilateral Development Banks. International Institute for Energy Conservation, Washington,
DC, September 1991.
RCG/Hagler, Bailly, Inc. (1993). Report 1: Externalities Screening and Recommendations, New York
State Environmental Externalities Cost Study, ESEERCO Project EP91-50, December, 1993.
References
135
Reddy, A.K.N., and Goldemberg, J. (1990), "Energy for the Developing World". Scientific American,
September, 1990.
Savitz, DA. (1993). "Overview of Epidemiological Research on Electric and Magnetic Fields and Cancer",
American Industrial Hygiene Association Journal, 54(4) p. 197-204.
Schipper, L., and S. Meyers (1992), Energy and Human Activity: Global Trends and Prospects.
Cambridge University Press, New York, NY, USA, 1992.
Smith, K.R., M. A. K. Khalil, R. A. Rasmussen, et al. (1992). “Greenhouse Gases from Biomass and
Fossil Fuel Stoves in Developing Countries: A Manila Pilot Study". Chemosphere, 1992
Smith, K.R. (1987), Biofuels, Air Pollution, and Health: A Global Review, Plenum Press, New York,
N.Y.
Starr, Rudman and Whipple. (1976). “Philosophical Basis for Risk Analysis”. Annual Review of Energy,
Volume 1, p. 629-662.
Stockholm Environment Institute (1991), An Outline of the Stockholm Environment Insitute’s
Coordinated Abatement Strategy Model (CASM). SEI, Stockholm, Sweden.
Stockholm Environment Institute -- Boston (1995), “Environmental Data Base (EDB): A listing of Core
Database Coefficients, May.
Subak, S., P. Raskin, and D. Von Hippel (1992), National Greenhouse Gas Accounts: Current
Anthropogenic Sources and Sinks. Stockholm Environment Institute Report, 1992.
Tibesar, A., and R. White (1990), "Pricing Policy and Household Energy Use in Dakar, Senegal". The
Journal of Developing Areas, 25, October 1990, pp. 33-48.
Union of Concerned Scientists, Natural Resources Defense Council, Alliance to Save Energy, American
Council for an Energy Efficient Economy, and Tellus Institute (1991), America's Energy Choices:
Investing in a Strong Economy and a Clean Environment. Union of Concerned Scientists, Cambridge,
MA, USA.
United Nations Environment Programme (1989). Environmental Data Report, Second Edition, Basil
Blackwell, Oxford, UK.
United Nations Environment Programme (UNEP) (1987), Montreal Protocol on Substances that Deplete
the Ozone Layer. UNEP conference series number 87-6106.
United States Congress, Office of Technology Assessment, (OTA, 1989). Biological Effects of Power
Frequency Electric & Magnetic Fields -- Background Paper, OTA-BP-E-53, Washington, DC., USA.
United States Congress, Office of Technology Assessment, (OTA, 1991). Energy In Developing
Countries. Report No. OTA-E-486, U.S. Government Printing Office, Washington, D.C., USA. January,
1991.
136
A Guide to Environmental Analysis For Energy Planners
United States Department of Commerce (1992), Statistical Abstract of the United States 1992. U.S.
Government Printing Office, Washington, D.C., USA.
United States Department of Energy. (DOE, 1983). Energy Technology Characterizations Handbook:
Environmental Pollution and Control Factors. Third Edition. U.S. Department of Energy, Washington
D.C., USA.
U.S. Environmental Protection Agency, (USEPA, 1985). Compilation of Air Pollutant Emission Factors,
Volumes I and II (plus supplements). USEPA, Washington, D.C., USA. Report # AP-42.
United States Environmental Protection Agency (USEPA, 1986), Guideline on Air Quality Models.
USEPA Office of Air and Radiation, Office of Air Quality Planning and Standards, Research Triangle
Park, North Carolina, USA. Report number EPA-450/2-78-027R, originally published July 1986, revised
with "Supplement A" (July 1987) and "Supplement B" (February, 1993).
U.S. Environmental Protection Agency (USEPA, 1990a), Methane Emissions from Coal Mining, Issues
and Opportunities for Reduction. Report # EPA/400/9-90/008, September, 1990. USEPA Office of Air
and Radiation.
U.S. Environmental Protection Agency (USEPA, 1990b), Emissions and Cost Estimates for Globally
Significant Anthropogenic Combustion Sources. Report # EPA/600/7-90/010, May, 1990. USEPA Air
and Engineering Research Laboratory, Research Triangle Park, North Carolina.
United States Environmental Protection Agency (USEPA, 1990c). Policy Options For Stabilizing Global
Climate, edited by D.A. Lashof and D. Tirpak. Report # 21P-2003.1, December, 1990. USEPA Office of
Planning and Evaluation, Washington D.C.
U.S. Environmental Protection Agency (USEPA, 1992), AIR CHIEF CD_ROM User's Manual, Version
2.0 Beta. Report # EPA/450/4-92/015, May, 1992. USEPA Office of Air Quality Planning and
Standards, Research Triangle Park, North Carolina.
Veldt, C., and Bakkum, A. (1988), EEC - DG XI - CORINAIR Emission Factors. Commission of the
European Communities, DG XI. Report # 88-355/R.22/CAP, November, 1988.
Von Hippel, D. and B. Granda (1992), Application of the LEAP/EDB Energy/Environment Planning System in
Costa Rica. Stockholm Environment Institute Report--Working Paper Energy, Environment and Development
Series - No. 18. Written collaboratively with the Latin American Energy Organization (OLADE).
Wigley, T., Holt, T., Raper, S. (1991) STUGE, an Interactive Greenhouse Model. Climate Research Unit,
University of East Anglia, Norwich, U.K.
World Bank (1992). World Development Report. World Bank, Washington, D.C., USA.
World Bank. Environmental Assessment Sourcebook, Volumes I-III, Environment Department, World
Bank Technical Paper 139, Washington DC, 1991.
World Health Organization (1989), Management and Control of the Environment, Report WHO/PEP/89,
Geneva, Switzerland.
References
137
World Health Organization (1982), Rapid Assessment of Sources of Air, Water, and Land Pollution
World Health Organization, Geneva, Switzerland. WHO Offset Publication No. 62.
World Health Organization and United Nations Environment Programme (1994), “Air Pollution in the
World’s Megacities”. Environment, Volume 36, #2, pages 4 to 37.
World Resources Institute (1992), World Resources 1992-93, Oxford University Press, New York/Oxford,
1992.
Z. Zhang (1991), Evolution of Energy Demands and CO2 Emissions in China Up to the Year 2030.
Netherlands Energy Research Foundation (ECN), Petten, The Netherlands, 1991.
138
A Guide to Environmental Analysis For Energy Planners
139
APPENDIX A:
ANNOTATED LIST OF LITERATURE REFERENCES USED IN
COMPILING THE ENVIRONMENTAL DATABASE (EDB)
Author:
Air Resources Board - State of California
Year:
Title:
Publisher:
Other Info:
1982
Methods for Assessing Area Source Emissions in California
Air Resources Board - State of California
Includes all revisions through December 1984
Notes:
Includes emission factors for various types of "area sources" -- sources of emissions that
individually release small amounts of a pollutant but collectively release significant emissions -in both the energy and non-energy sectors. Sources of emissions covered range from asphalt
roofing to residential fuel use to open burning of agricultural wastes. Data for many sources are
derived from values obtained from the USEPA (see the EPA "AP-42" document referenced
below), but specific values for and from California are included as well. A September 1991
Update is available.
[0 M]
Author:
Air Resources Board - State of California (CARB)
Year:
1990
Title:
Instructions for the Emission Data System Review and Update Report. Appendix III: Source
Classification Codes and EPA/NEDS Emissions Factors.
Publisher:
Other Info:
Air Resources Board - State of California
Dated March 1990.
Notes:
Provides two sets of emission factors: 1) emission factors used by EPA for the National
Emission Data System (NEDS) as published in "Criteria Pollutant Emission Factors for the 1985
NAPAP Emissions Inventory," and 2) emission factors based on information in the EPA AP-42
document (referenced below).
[0 A]
Authors:
Bocola W. and Cirillo M.C.
Year:
Title:
Publisher:
1989
Air pollutant emissions by combustion processes in Italy.
In Atmospheric Environment, Vol. 23, 227-245
Notes:
Includes emission factors used in compiling inventory of air emissions for Italy. Most air
emission values are from the CORINAIR Database.
[0 A]
140
A Guide to Environmental Analysis For Energy Planners
Author:
Bose, R.K., and V. Srinivasachary
Year:
1991
Title:
Policies to Reduce Energy Use and Environmental Emission in the Transport Sector: A Case of
Delhi City.
Publisher:
Other Info:
Tata Energy Research Institute, New Delhi, India
Unpublished manuscript
Notes:
Provides emission factors used in analysis conducted with LEAP/EDB, while Dr. Bose was a
visiting Scientist at the UNEP Centre, RISO National Lab, Denmark. These emission factors are
applicable to vehicles in India and perhaps other developing countries. One of the main
technical sources used was the Indian Institute of Petroleum report, "State of Art Report on
Vehicle Emissions," Dehradum, 1985.
[0 A]
Authors:
Butcher, S., Rao, U., Smith, K.R., Osborn, J., & Azuma, P.
Year:
Title:
1984
Emissions Factors and Efficiencies for Small-scale Open Biomass Combustion: Toward
Standard Measurement Techniques
Annual Meeting of the American Chemical Engineering Society
Publisher:
Notes:
Describes methods for collecting emissions data for small biomass combustion sources, including
residential biomass stoves. Includes limited emissions data based on field measurements.
[2 M]
Author:
California Air Resources Board
Year:
Title:
Publisher:
1986
[still need to enter the complete reference]
Other Info:
[40 M]
Author:
California Air Resources Board (CARB)
Year:
Title
1991
Identification of Volatile Organic Compound Species Profiles: ARB Speciation Manual,
Second Edition.
CARB, Sacramento, California, USA
Volume 1 of 2
Publisher:
Other Info:
Notes:
Provides data to estimate the emissions of specific species of volatile organic compounds (VOCs)
assuming that an overall VOC emission factor is available. Both energy and non-energy-sector
sources are covered, with different numbers of specific organic compounds identified per source.
Includes data from the USEPA as well as California-specific information.
[10 M]
141
Author:
California Energy Commission, Existing Power Plants
Year:
Title:
Publisher:
Other Info:
1989
Emission Factors for Existing California and Existing Out of State Power Plants
California Energy Commission, Sacramento, California, USA
Final Version
Notes:
Provides emission factors for current stock of power plants in California and other Western
States.
[80 M]
Author:
California Energy Commission, Generic Power Plants
Year:
Title:
Publisher:
Other Info:
1989
Staff Recommendations for Generic Power Plant Emission Factors
California Energy Commission, Sacramento, California, USA
Final Version
Notes:
Summary information for air pollutant emission factors for generic new power plants. Covers
both conventional fossil-fueled plants and some newer technologies (e.g. combined-cycle and
biomass-fueled plants).
[6 M]
Author:
California Energy Commission, Characterization Worksheet
Year:
Title:
Publisher:
1990
Electric Generation Characterization Worksheet
California Energy Commission
Other Info:
DRAFT, not to be quoted
Author:
Centre D'Etude sur L'Evaluation de la Protection dans le Domaine Nucleaire (CEPN)
Year:
Title:
Publisher:
Other Info:
1987
BATEX user manual
CEPN, Fontenay-aux-Roses (Near Paris), France
Model of accidental releases (document is in French).
Notes:
User's Guide to BATEX model of dispersion of materials accidentally released to the air (e.g. via
an explosion).
[0 M]
Author:
Year:
Title:
Publisher:
Other Info:
Commission of European Communities
1988
Radiation Protection - The Impact of Conventional and Nuclear Industries on the
Population: A Comparative Study of the Radioactive
CEC Directorate General for Science, Research and Development, Brussels, Belgium
Report Number EUR 10557 EN Contract BIO.F.320.81.F
Notes:
Contains information on radioactive emissions from energy technologies.
Author:
Corinair Inventory -- Commission of the European Community
[0 M]
[0 M]
142
A Guide to Environmental Analysis For Energy Planners
Year:
1992
Title:
Default Emission Factor Handbook.
Publisher:
Other Info:
Commission of the European Community, Brussels, Belgium
Updated periodically
Notes:
CORINAIR is an international (EC member states) effort to assemble consistent national
inventories of air pollutant emissions, including sulfur and nitrogen oxides, and VOCs. This
document presents the emission factors used in this effort, which covers stationary (e.g. power
plants, industrial facilities, household emissions), agricultural, road transportation (broken down
into hot emissions, cold starts, and evaporative emissions ), and natural sources. These sources
include some non-energy sector activities. This documents is one of the primary Europe-specific
sets of emission factor data. Gordon Mackenzie and Mette S. Olufsen at the UNEP Collaborating
Centre on Energy and Environment, at RISO National Laboratory in Denmark, used data in this
document to set up the EDB Corinair demand/transformation data.
[1154 A]
Authors:
Year:
Title:
Publisher:
Other Info:
DeLuchi, M.A, Johnston, R.A, Sperling, D.
Transportation Fuels and the Greenhouse Effect
Division of Environmental Studies, University of. California, Davis, CA, USA
Transportation Research Record 1175 p33
Notes:
Provides a comparison on the relative greenhouse-gas emissions from both conventional and
biomass-based transportation fuels.
[0 M]
Authors:
Year:
Title:
DeLuchi, M.A, Johnston, R.A, Sperling, D.
1988
Methanol versus Natural Gas Vehicles: A Comparison of Resource Supply, Performance,
Emissions, Fuel Storage, Safety, Costs and Tr
University of California, Davis, CA.
SAE Technical Paper Series 881656 - International Fuels and Lubricants Meeting and
Exposition, Portland, Oregon, Oct. 1988
Publisher:
Other Info:
Notes:
Includes emission factor information on methanol and natural gas vehicles. These authors have
published widely on the topic of alternative-fuel vehicles.
[0 A]
143
Author:
Year:
DeLuchi, M.A.
1991
Title:
Emissions of Greenhouse Gases from the Use of Transportation Fuels and Electricity, Volumes 1
& 2.
Publisher:
Other Info:
Center for Transportation Research, Argonne National Laboratory
Dated November 1991. Report number ANL/ESD/TM-22, Vol. 1 & 2. DeLuchi is
affiliated with the Institute of Transportation Studies, University of California, Davis.
Notes:
Provides estimate of the full fuel-cycle emissions of greenhouse gases from transportation fuels
and electricity. Covers emissions of carbon dioxide, methane, carbon monoxide, nitrous oxide,
nitrogen oxides, and non-methane organic compounds. Compares emissions from gasoline and
diesel fuels cycles with emission from: methanol from coal, natural gas, or wood; compressed or
liquefied natural gas; synthetic natural gas from wood; ethanol from corn or wood; liquefied
petroleum gas from oil or natural gas; hydrogen from nuclear or solar power; electricity from
coal, uranium, oil, natural gas, biomass, or solar energy, used in battery-powered electric
vehicles; and hydrogen and methanol used in fuel-cell vehicles.
[0 A]
Authors:
Dohan, M.R, Philip, P.F, with Lee, J, and Smith, M. Energy Systems Analysis Group
(BNL) and Urban and Policy Sciences Program (SUNY)
1974
The Effect of Specific Energy Uses on Air Pollutant Emissions in New York City: 19701985
Brookhaven National Laboratory, BNL/ SUNY New York Regional Energy Study, New
York
BNL Report Number 19064
Year:
Title:
Publisher:
Other Info:
Notes:
Commonly cited early source of emission factors on which data in some later compendia are
based.
[0 M]
Author:
Year:
Economopoulos, Alexander P.
1993
Title:
Assessment of Sources of Air, Water, and Land Pollution: A Guide to Rapid Source Inventory
Techniques and their Use in Formulating Environmental Control Strategies.
Publisher:
World Health Organization, Geneva, Switzerland
Other Info:
This is a two part report. Part One: Rapid Inventory Techniques in Environmental Pollution.
Part 2: Approaches for Consideration in Formulating Environmental Control Strategies.
WHO/PEP/GETNET/93.1A & B.
Notes:
This document updates the 1982 WHO document listed below. It provides a comprehensive
approach for evaluating air emission inventories and controls, liquid waste inventories and
controls, and solid waste inventories. It presents metrologies which can be used to make an
initial appraisal of the sources and levels of emissions from an area that has little or no previous
pollution load data -- i.e. particularly in developing countries. It relies on data from Corinair, the
USEPA AP-42 documents, and other sources.
[0 A]
Author:
Year:
Ellegard, Anders
1989
144
Title:
Publisher:
Other Info:
A Guide to Environmental Analysis For Energy Planners
Air Pollution and Coal Use in Maputo: Maputo Coal Stove Project: Summary of
Environmental Investigations
Beijer Institute/Stockholm Environment Institute
Final version based on "COAL STOVE EMISSIONS: Results From Investigations at the
Swedish Testing Institute", working paper #7, 1988
Notes:
Provides measured emission factors for household coal-fired stoves (data collected in Africa),
with limited additional data for biomass-fired stoves.
[39 A]
Author:
Year:
Title:
Publisher:
Other Info:
Ellegard, Anders, and Jose Lopes
1990
Quick and Dirty: The Maputo Coal Stove Project 1985-89
Stockholm Environment Institute
SEI Energy, Environment and Development Series Report No. 1. Published in
collaboration with the Swedish International Development Authority (SIDA).\
Notes:
Provides measured emission factors for household coal-fired stoves (data collected in Africa),
with limited additional data for biomass-fired stoves.
[0 A]
Author:
Year:
Title:
Publisher:
Other Info:
Expertengruppe Energieszenarien/ Groupe d'Experts Scenarios Energetique
1988
Energieszenarien/ Scenarios Energetiques
Expertengruppe Energieszenarien/ Groupe d'Experts Scenarios Energetique
Mogliuchkeiten, Voraussetzungen und Konsequenzen eines Ausstiegs der Schweiz aus der
Kernenergie/ (In French and German)
Notes:
Provides energy scenarios and some emission factors for Switzerland in the context of a
prospective study of emissions for the country.
[0 M]
Authors:
Year:
Title:
Publisher:
Gleick P.H., Morris G.M., Norman A.N.
1989
Greenhouse Gas Emissions from the Operation of Energy Facilities
Prepared for the Independent Energy Producers Association, Sacramento, CA, USA.
Notes:
List emission factors for several types of greenhouse gasses for different types of Energy
Facilities, with an emphasis on electric power plants of types used in or proposed for California.
[0 M]
145
Authors:
Year:
Title:
Publisher:
Holdren J. P., G. Morris, and I. Mintzer
1980
Environmental Aspects of Renewable Energy Sources
In Annual Review of Energy, 1980, v.5 p. 241-291
Notes:
Fairly comprehensive early work on full-fuel cycle emissions from renewable energy systems,
including biomass energy and other solar energy fuel cycles.
[0 A]
Author:
Year:
Title:
Publisher:
Other Info:
ICF Incorporated
1989
ASF - The Atmospheric Stabilization Framework User's Guide and Software Description
ICF Incorporated, Fairfax, Virginia, USA
1989 Version in Draft Form - Contains data files of emission factors used in USEPA's
ASF study.
Notes:
User's Guide contains a wealth of information on models of greenhouse gas emissions and effects
and on background data for ASF's global inventory of GHGs, as well as the emission factor data
files for select greenhouse gas emissions (carbon dioxide, carbon monoxide, nitrogen oxides,
nitrous oxide, methane) from a wide variety of sources of GHGs. Also contains data on the
effectiveness of technologies for reducing GHG emissions. Most of the emissions data included
here were derived from earlier versions of Radian, 1990, and from other USEPA documents.
Some of the materials in this volume were subsequently published as a "Technical Appendix"
Volume to the USEPA study Policy Options for Stabilizing Global Climate, USEPA Report
Number 21P-2003.3, December, 1990.
[0 A]
Author:
Year:
Title:
Publisher:
Other Info:
ICF Resources Incorporated
1990
Methane Emissions to the Atmosphere from Coal Mining
ICF Resources Inc., Fairfax, VA
Report to USEPA Office of Air and Radiation; released as USEPA report number
EPA/400/9-90/008, September, 1990. USEPA, Washington, D.C., USA.
Notes:
Provides emission factors for surface and underground mining, plus a discussion of emissions of
methane from coal mining in each mining state of the United States and from other major coalproducing nations. Also provides a discussion of the factors that influence methane emissions
from coal mining.
[12 M]
Author:
Year:
Title:
Publisher:
IEA and OECD
1990
Climate Change: The Energy Dimension
The International Energy Agency and the Organization for Economic Co-operation and
Development (IEA and OECD), Paris, France.
Emission factor data largely based on Radian 1987.
Other Info:
Notes:
[0 A]
146
Author
Year
Title:
Publisher:
Other Info:
A Guide to Environmental Analysis For Energy Planners
Intergovernmental Panel on Climate Change (IPCC)
1990
International Workshop on Methane Emissions from Natural Gas Systems, Coal Mining,
and Waste Management Systems", April 9-13, 1990.
Workshop funded by the Environment Agency of Japan, USAID, and USEPA.
Document available through the USEPA Office of Policy, Planning and Evaluation-Climate Change Division.
Notes:
The papers presented provide data on methane emissions from the indicated sources. Some
estimates of national and global average emission factors and leakage rates are presented. A
summary of this workshop was published as Methane Emissions and Opportunities for Control,
USEPA report number EPA/400/9-90/007, September 1990.
[10 M]
Author:
Year:
Title:
Publisher:
Other Info:
Islam, N.
1987
Test of Combustion Properties and Pollutant Emissions of Lignite Briquettes
Resource Systems Institute, East-West Center, Honolulu, Hawaii, USA
Notes:
Provides emissions test data for combustion of lignite (coal) briquettes of types that could be used
in household coal stoves in developing countries.
[3 M]
Author:
Year:
Title:
Publisher:
Other Info:
Meridian Corporation
1988
Energy System Emissions and Material Requirements
Prepared for US Department of Energy, Washington DC, USA
DRAFT - for the Deputy Assistant Secretary for Renewable Energy, DOE
Notes:
Provides information on the relative environmental emissions and material requirements of
several different energy systems, including both renewable and fossil-fueled technologies.
[0 M]
Authors:
Year:
Title:
Publisher:
Other Info:
Mintzer I., Hedman S., Miller A., Bowser R.
1990
Externalities Associated with Electric Power Supply and Demand-Side Technologies
Center for Global Change, University of Maryland, College Park, MD, USA
Working Paper
Notes:
Provides information on the relative environmental emissions and other externalities associated
with options for both saving electricity through demand-side management technologies and for
generating electricity using power plants. Emission factors and technological comparisons are
provided for a number of different systems.
[0 M]
Author:
Year:
Title:
Morris, S.C, Novak, K.M. (Regional Energy Studies Program, BNL)
1977
Databook for the Quantitative Health Effects From Coal Energy Systems
147
Publisher:
Other Info:
Brookhaven National Laboratory (BNL)/ US Department of Energy (USDOE)
For National Coal Utilization Assessment BNL 23606 Information Report, 1977
Notes:
Early work describing health effects of coal energy systems. Part of a large energy and
environment modeling project that took place at BNL in the 1970's and 1980's.
[0 M]
Author:
Year:
Title:
Publisher:
Other Info:
Moscowitz, C. M.
1978
Source Assessment: Charcoal Manufacturing, State of the Art
Environmental Protection Agency
Notes:
Provides air pollutant emission factors for several types of commercial US charcoal-making kilns.
[18 M]
Author:
Year:
Title:
OECD, Air Policy Management Group
1988
The Motor Vehicles Project: Control of Emissions from In-use Vehicles: Technical
Background Paper
Organization for Economic Co-operation and Development (OECD) Environmental
Directorate, Paris, France.
Meeting Room Document. No. 1 for the 37th meeting, Paris, 25-26 Oct.
Publisher:
Other Info:
Notes:
Author:
Year:
Title:
Publisher:
Other Info:
Notes:
[0 M]
OECD, Air Policy Management Group
1989
Control of Major Air Pollutants - A Study of Long Range Transport of Photochemical
Oxidants Across Europe
Organization for Economic Co-operation and Development (OECD) Environmental
Directorate, Paris, France.
ENV/AIR/88.8 (1st version) - Restricted - Also published from the 37th meeting, 25-26
Oct.
Focus is on the fate of acid rain precursors (nitrogen and sulfur oxides) emitted in Europe.
Includes some limited emission factor data for NOx and SOx emissions from major sources.
[0 M]
148
Author:
Year:
Title:
Publisher:
A Guide to Environmental Analysis For Energy Planners
OECD, Compass Project
1983
Environmental Effects of Energy Systems
Organization for Economic Co-operation and Development (OECD) Environmental
Directorate, Paris, France. OECD, Paris
Other Info:
Notes:
This document is a mostly-qualitative summary of the environmental externalities associated
with the construction and use of energy systems, with some limited quantitative data on air
emissions and other environmental impacts.
[0 A]
Author:
Year:
Title:
Publisher:
OECD, Compass Project
1985
Environmental Effects of Electricity Generation
Organization for Economic Co-operation and Development (OECD) Environmental
Directorate, Paris, France. OECD, Paris
Other Info:
Notes:
A primarily descriptive summary of the environmental effects of electricity generation, with some
limited generic quantitative data on power plant emission factors.
[0 A]
Author:
Year:
Title:
Publisher:
OECD, Compass Project
1986
Environmental Effects of Automotive Transport.
Organization for Economic Co-operation and Development (OECD) Environmental
Directorate, Paris, France. OECD, Paris
172 pp.; published in English
Other Info:
Notes:
This document provides a mostly-qualitative summary of the environmental effects of automotive
transport, primarily from a developed-country point of view. Some generic emission factors are
provided for typical European motor vehicle.
[7 A]
Author:
Year:
Title:
Publisher:
OECD, Compass Project
1988
Environmental Impacts of Renewable Energy
Organization for Economic Co-operation and Development (OECD) Environmental
Directorate, Paris, France.
Other Info:
Notes:
Like the other volumes in the "Compass" series this document provides a qualitative summary of
the environmental effects of renewable energy systems, with a few examples in which impacts or
emissions are quantified.
[0 A]
149
Author:
Year:
Title:
Publisher:
Other Info:
OECD, Environment Directorate, Air Policy Management Group
1989
Control of Major Air Pollutants - Emissions Inventory for OECD Europe
Organization for Economic Co-operation and Development (OECD) Environmental
Directorate, Paris, France.
From the 37th meeting of the Group, 25-26 Oct.. Not a final draft. Marked
RESTRICTED
Notes:
Documents the process used to produce a preliminary inventory of air pollutants for OECD
Europe. Includes a listing of the emission factors used to produce the inventory. Many of the
factors used were derived from USEPA figures, although much Europe-specific information is
also included.
[0 M]
Author:
Year:
Title:
Publisher:
Other Info:
ÖKO Institute
1990
TEMIS model and miscellaneous papers
ÖKO Institute, Darmstadt, Germany
TEMIS is the Total-Emission-Model for Integrated Systems. TEMIS has been released in
the US in cooperation with the USDOE. Most of the papers and manuals covering
TEMIS are available in both English and German.
Notes:
TEMIS is a software tool designed to compare the relative fuel cycle energy use and emissions
that occur as a consequence of using alternative methods providing an energy service. An
example application might be the comparison of emissions per GJ of heat delivered home heating
using fuel oil versus home heating using electric resistance heat. TEMIS includes a database of
emission factors for several key air pollutants, plus solid wastes and some other environmental
impacts. This database includes quantitative information from many sources, including a good
deal of emission factor information from Germany.
[0 A]
Author:
Year:
Title:
Publisher:
ORNL: Oak Ridge National Laboratory, G. Marland et al.
1989
Estimates of CO2 Emissions from Fossil Fuel Burning and Cement Manufacture...
ORNL/CDIAC (Carbon Dioxide Information Analysis Center), Oak Ridge National
Laboratory, Oak Ridge, TN, USA
Report # ORNL/CDIAC-25
Other Info:
Notes:
This volume presents estimates of carbon dioxide emissions from the combustion of solid, liquid,
and gaseous fossil fuels, as well as from natural gas flaring from oil wells and from cement
production, for virtually all countries of the globe. Data sets start as early as 1950, and run
through 1987 (data for later years are available in diskette form). Estimates for energy sector
carbon dioxide emissions are based on energy production and import/export data obtained from
the United Nations. This volume includes general carbon dioxide emissions factors for fossil
fuels and for cement manufacture that are widely used by other researchers in the climate-change
field. and also includes a thorough write-up of how the ORNL emissions inventory, and the
emission factors used in it, are derived.
[56 A]
Author:
Year:
PASZTOR, J. and KRISTOFERSON, L. (eds)
1990
150
A Guide to Environmental Analysis For Energy Planners
Title:
Publisher:
Other Info:
Bioenergy and the Environment
Westview Press, Boulder CO., USA
Notes:
This book provides an overview of many of the environmental issues surrounding the production
and use of biofuels. It is divided into sections focusing on "The Fuels" (e.g. traditional fuels,
modern fuels, liquid fuels, biogas) and "Effects on the Environment" (air pollution, water
pollution, socioeconomic impacts, and others). Both qualitative and quantitative information is
provided, including some emissions coefficients for biomass combustion and other biomass
energy systems.
[2 A]
Author:
Year:
Title:
Publisher:
Other Info:
Radian Corporation
1987
1987 Symposium on Stationary Combustion Nitrogen Oxide Control
Radian Corporation, Research Triangle Park, North Carolina, USA
Volumes I and II
Notes:
Includes papers that describe options for control of nitrogen oxide (NOx) emissions, with
technology descriptions, and estimates of the percentage reduction in NOx emissions through use
of the control devices, and, in some cases, estimates of the costs of pollution control equipment.
[0 M]
Author:
Year:
Title:
Radian Corporation
1990
Emissions and Cost Estimates for Globally Significant Combustion Sources of NOx,
N2O), CH4, CO, and CO2.
US EPA, Office of Policy, Planning, and Evaluation.
EPA Report # EPA-600/7-90-010, May 1990, EPA Contract No. 68-02-4288
Publisher:
Other Info:
Notes:
Includes emission factors for the greenhouse gasses (GHG) listed above for combustion of fuels
by equipment in the utility, industrial, fuel production, transportation, residential, and
commercial sectors, as well as for large industrial kilns, ovens, and dryers. Also included are
data on the relative costs and efficiency of devices and technologies for controlling GHG
emissions. This document is the source of much of the emission factor data used in the USEPA's
Atmospheric Stabilization Framework study, as well as other inventory efforts. Most of the
(non-CO2) emission factors contained here are derived from the USEPA "AP-42" emission factor
compendium.
[3 M]
151
Author:
Year:
Title:
Publisher:
Other Info:
Radian Corporation (Weaver, C.S, Klausmeier, R.F, Kishan, S.)
1986
Estimation of Energy-Specific CO and NOx Emission Factors for the World Vehicle Fleet:
1960-2025
Radian Corporation, Sacramento, CA, USA
Dated March 6, 1986. Prepared. under EPA Contract No. 68-02-3994.
Notes:
Provides estimates of past, present and future emission factors for carbon monoxide and nitrogen
oxides, two of the most important pollutants from automobile engines, for the world's vehicle
fleet. Emissions factors are provide for 6 regions (USA; Western Europe/Canada;
Japan/Australia/New Zealand; Soviet Union/Eastern Europe; China; and Rest of World).
Estimates of CO and NOx emissions were developed for a number of generic automotive
technologies using emissions and fuel-economy data from EPA's MOBILE3 model (i.e. the
USEPA "AP-42" Vol. 2 emission factor compendium).
[0 A]
Author:
Year:
Title:
Radian Corporation, Research Triangle Park, N.C.
1987
Criteria Pollutant Emissions Factors for the 1985 NAPAP (National Acid Precipitation
Assessment Program) Emissions Inventory
U.S. National Technical Information Service, Springfield, VA
USEPA Report # EPA/600/7-87/015; NTIS Report # PB87-198735
Publisher:
Other Info:
Notes:
This database, which is primarily derived from the USEPA AP-42" series of reports, presents in
concise form emission factors for the "criteria" air pollutant emissions (nitrogen and sulfur
oxides, VOCs, carbon monoxide, particulate matter, and in some cases lead) for stationary
sources of emissions. These sources of emissions include facilities and equipment in both the
energy sector as well as industrial and other non-energy processes (e.g. solvent use, sintering of
metals, manufacture of chemicals).
[0 A]
Author:
Year:
Title:
Publisher:
Other Info:
Safriet D.W. - EPA project officer
1989
Estimating Air Toxic Emissions from Coal and Oil Combustion Sources
EPA, Research Triangle Park, NC, USA
EPA-450/2-89-001
Notes:
Provides methods, emission factors and speciation fractions (i.e. what fraction of total
hydrocarbons is made up of a specific toxic hydrocarbon species) to enable the estimation of
emission factors for toxic substances derived from oil and coal combustion.
[0 M]
152
A Guide to Environmental Analysis For Energy Planners
Author:
Year:
Title:
Publisher:
Smith, Kirk R.
1987
Biofuels, Air Pollution, and Health: A Global Review
Plenum Press, New York, N.Y., USA
Notes:
Excellent review of the environmental and human-health impacts of biofuels use, with a
particular emphasis on environmental and health effects in developing countries. Also contains
some secondary source material that is otherwise difficult to obtain on emissions factors for coal
and biofuel consumption in the types of household stoves found in developing countries. [94 M]
Author:
Year:
Smith, Kirk R., et al.
1992
Title:
Greenhouse Gases from Biomass and Fossil Fuel Stoves in Developing Countries: A Manila
Pilot Study.
Publisher:
Chemosphere
Notes:
Discusses the results of tests on a total of 24 samples, 14 cookstoves. The cookstoves tested were
fueled by LPG, kerosene, charcoal, and wood. Emissions of carbon dioxide, carbon monoxide,
methane, nitrogen oxides, and total non-methane organic compounds were analyzed. The author
is currently conducting larger more detailed studies in India and China.
[0 A]
Author:
Year:
Smith, Kirk R., et al.
1992
Title:
Greenhouse Gases from Small-Scale Combustion in Developing Countries: A Pilot Study in
Manila .
Publisher:
Other Info:
U.S. Environmental Protection Agency, Office of Research and Development
EPA report: EPA-600-R-92-005.
Notes:
Discusses the results of tests on a total of 24 samples, 14 cookstoves. The cookstoves tested were
fueled by LPG, kerosene, charcoal, and wood. Emissions of carbon dioxide, carbon monoxide,
methane, nitrogen oxides, and total non-methane organic compounds were analyzed. Report
included detailed results from the tests.
[0 A]
Authors:
Year:
Title:
Publisher:
Other Info:
Sperling, D, DeLuchi, M.A.
1989
Transportation Energy Futures
University of California, Davis, CA, USA
Also in Annual Review of Energy, 1989.
Notes:
Provides a forward-looking view of transportation systems and technologies, particularly for the
United States and other developed countries. Provides some limited information on emission
factors for new and upcoming vehicles, including those using fuels other than diesel oil and
gasoline-fueled transportation.
[0 A]
Author:
Year:
Stockholm Environment Institute - Boston Center (TELLUS Institute)
1990
153
Title:
Publisher:
Calculated based on assumptions listed in note for specific entry
(None)
Notes:
This note indicates that the value, rather than being derived from a specific reference document,
was estimated by the Stockholm Environment Institute--Boston Center based on specific
assumptions as listed in the notes for the specific entry.
[357]
Author:
Year:
Title:
Publisher:
Stockholm Environment Institute--Boston Center (Tellus Institute)
1991
Calculations based on fuel carbon content
(None)
Notes:
This note indicates that the value, an estimate of carbon dioxide emissions per unit fuel
consumed, has been calculated at the Stockholm Environment Institute--Boston Center based on
fuel carbon-content assumptions as listed in the notes for the coefficient entry, and was thus not
based directly on any one particular literature source. Most of the carbon dioxide coefficients in
EDB were calculated in this manner, using default carbon content assumptions from LEAP, so a
to create a consistent set of CO2 emission factors within EDB.
[54]
Author:
Year:
Title:
Stockholm Environment Institute--Boston Center (G2S2)
1991
The Greenhouse Gas Scenario System (G2S2: Current Accounts Spreadsheet
ENERGY.XLS)
Stockholm Environment Institute--Boston Center (SEI-B), Boston, MA, USA
G2S2 Spreadsheet as of July, 1991.
Publisher:
Other Info:
Notes:
In the process of preparing the Greenhouse Gas Scenario System, a tool for estimating national,
regional. and global inventories of greenhouse gasses, estimates were made of national and
regional-average emission factors for various sectors, based primarily on energy data from the
OECD/IEA and on emission factors from the Atmospheric Stabilization Framework and other
sources. Some of these values are available as generic estimates in EDB.
[516]
Author:
Year:
Title:
Publisher:
Tellus Institute (Vermont Report)
1990
The Role of Hydro-Quebec Power in a Least-Cost Energy Resource Plan for Vermont
Tellus Institute, Boston, MA, USA
Other Info:
[26]
154
Author:
Year:
Title:
Publisher:
A Guide to Environmental Analysis For Energy Planners
Tellus Institute - Internal E-factors
1990
Master Emissions List for New Generic Facilities.
Tellus Institute, Boston, MA, USA
Other Info:
Author:
Year:
Title:
Publisher:
[0]
Tellus Institute - Manchester Street Report
1990
Evaluation of Repowering the Manchester Street Station
Tellus Institute, Boston, MA, USA
Other Info:
Author:
Year:
Title:
Publisher:
[4]
U. S. Congress, CAA
1990
Amended Clean Air Act
U. S. Government Printing Office, Washington, D.C., USA
Other Info:
Notes:
Describes 1990 United States regulations governing air pollutant emissions from energy
combustion and from other sources. For some sectors, provides maximum emission factors
permissible in the US for new and refurbished energy-using equipment.
[38]
Author:
Year:
Title:
U.S Environmental Protection Agency (USEPA) (Speciate)
1990
Volatile Organic Compound (VOC)/Particulate Matter (PM) Speciation Data System.
Version 1-32a
USEPA. Research Triangle Park, NC, USA
Prepared by Radian Corporation for USEPA. EPA Contract # 68-02-4286
Publisher:
Other Info:
Notes:
Computer database allowing estimation of atmospheric emission factors for particular organic
species and for specific size classes of particulate matter emissions (e.g. particulate emissions
under or over ten microns in diameter). Speciation profiles (or surrogate profiles) are available
for most of the sources of emissions described in the USEPA's "AP-42" series. In many cases,
profiles that have been measured for one source are used as default or surrogate values for similar
types of equipment. This database is available as part of the "AIR CHIEF" CD-ROM (optical
data storage) disk distributed by the EPA, and also as a part of the "CHIEF" computer bulletin
board system, run by the EPA from its Research Triangle Park office.
[11 M]
155
Author:
Year:
Title:
Publisher:
Other Info:
U.S. Department of Energy (ETH)
1983
Energy Technology Characterizations Handbook (ETH). Environmental Pollution and
Control Factors. Third Edition.
U.S. Department of Energy, Off. of Environmental Analysis, Washington D.C., USA
Report # DOE/EP-0093
Notes:
Large, well-referenced volume providing 1) characterizations of the fuel use, energy output,
materials and resource requirements (e.g. steel, land, water), and environmental "residuals" (air
pollutants, solid wastes, radiation, water-borne pollutants, health and safety) for several
categories of technologies, including nuclear, synthetic fuel, coal, petroleum, natural gas, solar,
geothermal, and hydroelectric technologies, and 2) characterizations of environmental control
technologies for coal-fired utility and industrial plants and for synthetic fuels technologies. Most
of the equipment discussed is of utility scale, and is geared to large-scale production of either
electricity or liquid fuels. This work is a good reference for environmental emission factors
beyond air pollutant emissions, though not every type of environmental impact is considered for
every type of energy system characterized. This volume had not been updated as of 1992.
[100 M]
Author:
Year:
Title:
Publisher:
Other Info:
U.S. Department of Energy/Energy Information Administration (SEDS)
1985
State Energy Data Report (SEDS)
DOE/EIA, Washington D.C., USA
Notes:
Presents data on energy use by state and sector for each state of the United States. This
information is the basis of the NAPAP (National Acid Precipitation Assessment Program)
Emissions Inventory done on an annual basis.
[103 M]
Author:
Year:
Title:
Publisher:
Other Info:
U.S. Department of Energy, Office of Environmental Analysis
1988
Energy Technologies and the Environment. Environmental Information Handbook
National Technical Information Service, Springfield, VA, USA
Report # DOE/EH-0077, dated 10/88
Notes:
This handbook covers many of the same technologies presented in the 1983 USDOE publication
Energy Technology Characterizations Handbook, as described above, but in a somewhat
different (more narrative) format. The 21 chapters cover coal-based, petroleum refining, oilshale, fuel cell, nuclear, solar, and biomass technologies, as well as advanced diesel engines.
Each chapter provides a narrative description of the technology and its environmental impacts,
with quantitative data on emissions and other impacts that varies in amount and coverage by
chapter. The handbook is a good source for those wishing an overview of specific (typically
large-scale) energy technologies and their environmental risks.
[54 M]
156
Author:
Year:
Title:
Publisher:
Other Info:
A Guide to Environmental Analysis For Energy Planners
U.S. Environmental Protection Agency (AP-42, Vol I)
1985
Compilation of Air Pollutant Emission Factors. Volume I: Stationary Point and Area
Sources
National Technical Information Service, Springfield, VA, USA
Volume I of report # AP-42, 4th edition; Updated frequently
Notes:
"AP-42" is the USEPA's central compilation of air pollutant emission factors for virtually all
significant sources of air pollution. Volume I of this series, together with its many supplements,
provides emission factors for a wide variety of both fuel-using and non-energy stationary
equipment, appliances, facilities and processes. The technologies covered range from coal-fired
power plants to propane heaters to charcoal kilns to processes for manufacturing specific
chemicals. The information in AP-42 is drawn on heavily by many other US and international
emission factor databases. Most of the information in AP-42 is based on the results of
emissions testing--tests commissioned by EPA or other agencies or reported in the scientific
literature. AP-42 provides qualitative guidelines (lettered "A" though "E") indicating the quality
of data for most sources. Most of the information in AP-42 is available on the AIR CHIEF CDROM (optical data storage) disk, and through the CHIEF computer bulletin board system.
Information on both of these products can be obtained through the USEPA office in Research
Triangle Park, North Carolina, USA.
[73 T]
Author:
Year:
Title:
Publisher:
Other Info:
U.S. Environmental Protection Agency (AP-42, Vol II)
1985
Compilation of Air Pollutant Emission Factors. Volume II: Mobile Sources
U.S. Government Printing Office, Washington, D.C., USA
Volume II of report # AP-42, 4th edition. Report is periodically updated; a 1991
Supplement is available.
Notes:
"AP-42" is the USEPA's central compilation of air pollutant emission factors for virtually all
significant sources of air pollution. Volume II of this series, together with its many
supplements, provides very detailed air pollutant emission factors for the types of gasoline- and
diesel-fueled vehicles and non-stationary equipment used in the United States. The volume is
divided into sections on "Highway Mobile Sources" (cars, trucks, buses, motorcycles) and "OffHighway Sources" (aircraft, locomotives, watercraft, utility engines, agricultural and heavy
equipment, and snowmobiles). Emission factors for carbon monoxide, nitrogen oxides, and nonmethane hydrocarbons are presented for all sources, and additional emission factors are presented
for some sources. A wealth of information is provided that allows emission factors to be
adjusted for altitude, the age of the vehicle, temperature, and other parameters. Much of the
emission factor information in EDB covering motor vehicles is derived from data in this
compilation. The reader should be warned, however, that much of the information in this
reference is very technical, and may require some interpretation in order to be used directly with
EDB and LEAP. The data in this volume is available in a software tool called MOBILE (the
latest version is MOBILE5), which allows the calculation of fleet-average emission factors for a
stock of automobiles described by the user.
[420 M]
Author:
Year:
Title:
Publisher:
U.S. Environmental Protection Agency (Radian-VOCs)
1988
Air Emissions Species Manual. Volume I. Volatile Organic Compounds Species Profiles
National Technical Information Service (NTIS), Springfield, VA, USA
157
Other Info:
Prepared by Radian Corp. Report # EPA-450/2-88-003a
Notes:
Provides information allowing estimation of atmospheric emission factors for particular organic
species (e.g. benzene or methane) based on overall VOC emissions for a particular source,.
Speciation profiles (or surrogate profiles) are available for most of the sources of emissions
described in the USEPA's "AP-42" series. In many cases, profiles that have been measured for
one source are used as default or surrogate values for similar types of equipment. This database
is available in electronic format as part of the "AIR CHIEF" CD-ROM (optical data storage) disk
distributed by the EPA, and also as a part of the "CHIEF" computer bulletin board system, run by
the EPA from its Research Triangle Park office.
[7 M]
Author:
Year:
Title:
Publisher:
Other Info:
U.S. Environmental Protection Agency
1988
Toxic Air Pollutant Emission Factors
USEPA
ATEF, Report Number EPA-450/2-88-006a
Notes:
Provides air pollutant emission factors for toxic substances emitted from a variety of sources,
including fuel-combustion sources.
[0 M]
Author:
Year:
Title:
Publisher:
Other Info:
U.S. Environmental Protection Agency (ASF)
1989
Atmospheric Stabilization Framework, Appendix A
USEPA Office of Policy, Planning, and Evaluation, Washington, D.C., USA
D. Tirpak and D. Lashof, Editors; draft form as of 2/90
Notes:
This Appendix contains information on models of greenhouse gas emissions and effects and on
background data for ASF's global inventory of GHGs, as well as the emission factor data files for
selected greenhouse gas emissions (carbon dioxide, carbon monoxide, nitrogen oxides, nitrous
oxide, methane) from a wide variety of sources of GHGs. Also included are data on the
effectiveness of technologies for reducing GHG emissions. Most of the emissions data included
here were derived from earlier versions of Radian, 1990, and from other USEPA documents.
Some of the materials in this volume (including the emission factor data files) were subsequently
published as a "Technical Appendix" Volume to the USEPA study Policy Options for Stabilizing
Global Climate, USEPA Report Number 21P-2003.3, December, 1990.
[488 A]
158
A Guide to Environmental Analysis For Energy Planners
Author:
Year:
Title:
Publisher:
Other Info:
U.S. Environmental Protection Agency
1989
Locating and Estimating Air Toxics Emissions from Municipal Waste Combustors
USEPA, Research Triangle Park, NC, USA
Report Number EPA-450/2-89-006
Notes:
This document provides 1) an overview of the municipal solid waste (MSW) combustion
industry, 2) emission factors for different types of (MSW combustion equipment, and a list of the
current and planned MSW combustion facilities in the United States. Emission factors are given
for acid gasses (e.g. nitrogen and sulfur oxides, hydrochloric acid), organic compounds, and toxic
metals. A description of the emission control technologies applicable to MSW combustion
facilities is also provided. This document is available on the "AIR CHIEF" CD-ROM (optical
data storage) disk distributed by the EPA, and also as a part of the "CHIEF" computer bulletin
board system, run by the EPA from its Research Triangle Park office.
[0 M]
Author:
Year:
Title:
U.S. Environmental Protection Agency (NEDS)
1989
NEDS (National Emissions Data System) Source Classification Codes and Emission
Factor File
USEPA Office of Air Quality Planning and Standards, Research Triangle Park, NC, USA
EPA dBASE III+ data files for criteria pollutants
Publisher:
Other Info:
Notes:
This database was the foundation of the national air pollutant inventory done in 1989 and before.
It consists of data for criteria air pollutants (CO, NOx,, VOCs, Particulates, SOx) with emission
factors for lead sometimes listed as well. It is derived primarily from the USEPA "AP-42"
compilation, and was used for many data values in EDB. The database is indexed by source
classification codes that pertain to the type of source equipment and the sector or sub-sector for
which the emission factor is applicable. This database is now included in the "Airs Facility
Subsystem" database of emission factors (see below).
[1034 M]
Author:
Year:
Title:
U.S. Environmental Protection Agency
1990
AIRS Facility Subsystem Source Classification Codes and Emission Factor Listing for
Criteria Air Pollutants
US EPA, Research Triangle Park, North Carolina 27711
Report number EPA 450/4-90-003
Publisher:
Other Info:
Notes:
This database is similar to and updates the NEDS database of emission factors described above.
Like NEDS, it primarily contains emission factor data for criteria air pollutants (CO, NOx,,
VOCs, Particulates, SOx), and is derived primarily from AP-42 data. The database is indexed
by source classification codes that pertain to the type of source equipment and the sector or subsector for which the emission factor is applicable.
[3 M]
Author:
Year:
Title:
Publisher:
U.S. Environmental Protection Agency
1993
Factor Information Retrieval (FIRE) System
US EPA, Research Triangle Park, North Carolina 27711
Other Info:
Prepared for the EPA by the Radian Corporation under EPA contract number: 68-D2-0160.
159
Notes:
FIRE is an easy to use pc program containing EPA's recommended criteria and hazardous air
pollutant emission estimation factors. FIRE contains information about industries and their
emitting processes, the chemicals emitted and emission factors themselves. It contains data on
the CAA criteria pollutants, 41 of the 189 HAPs specified in the CAAA, and 43 toxic air
pollutants. The main sources of data used in FIRE include: (1) SPECIATE -- data from the Air
Emission Species Database, which provides speciation factors for VOC and PM; (2) XATEF -data from the Crosswalk/Air Toxic Emission Factor (XATEF) database; (3) CARB -- data from
various report published by the California Air Resources Board (CARB) air regulatory initiative;
(4) AFSEF -- data from the Aerometric Information Retrieval System (AIRS) Facility Subsystem
(ASF) Emission Factor database; and (5) AP-42 -- data from the EPA's Compilation of Air
Pollutant Emission Factors, 4th ed., September 1985, including supplements A-F. [0 B]
Author:
Year:
Title:
Publisher:
U.S. Environmental Protection Agency
1993
Air CHIEF (Clearinghouse for Inventories and Emission Factors) CD-ROM
US EPA, Research Triangle Park, North Carolina 27711
Other Info:
Prepared for the EPA by the Radian Corporation under EPA contract number: 68-D2-0160.
Notes:
The Air Chief CD-ROM includes the EPA's Air CHIEF data base, the FIRE database, and a
number of WordPerfect and/or text formatted EPA documents (L&E's, AP-42 vol. 1, and various
background documents.) The Air CHIEF data base contains 26 EPA reports and 5 additional
datasets that can be used to assist in finding and estimating pollutant emissions.
[0 B]
Author:
Year:
Title:
Publisher:
Other Info:
UNEP
1985
Energy Supply/ Demand in Rural Areas in Developing Countries
United Nations Environment Programme (UNEP), Nairobi, Kenya - Energy Report Series
Energy Report Series, ERS-11-84, Report of the Executive Director
Notes:
[8 A]
160
A Guide to Environmental Analysis For Energy Planners
Author:
Year:
Title:
Publisher:
Other Info:
UNEP (Fossil Fuels)
1979
The Environmental Impacts of Production and Use of Energy, Part I: Fossil Fuels
United Nations Environment Programme (UNEP), Nairobi, Kenya.
ERS-14-85, Part IV Comparative Assessment of the Environmental Impacts of Energy
Sources
Notes:
Provides a primarily qualitative overview of the environmental impacts of the production and use
of fossil fuels. Some generic quantitative emission and impact figures, including air emission,
health and safety impacts, and solid wastes, are included as well.
[30 M]
Author:
Year:
Title:
Publisher:
Other Info:
UNEP (Nuclear)
1979
The Environmental Impacts of Production and Use of Energy, Part II: Nuclear Energy
United Nations Environment Programme (UNEP) - Energy Report Series, Nairobi, Kenya
Energy Report Series, ERS-2-79, Report of the Executive Director
Notes:
As with the volume on fossil fuels above, this document provides a primarily qualitative overview
of the environmental impacts of the production and use of nuclear energy. Some generic
quantitative data on emission from and impacts of the nuclear fuel cycle are provided as well.
[0 M]
Author:
Year:
Title:
Publisher:
Other Info:
UNEP / von Gehlen, K. (Oil Shale)
1985
The Environmental Impacts of Exploitation of Oil Shales and Tar Sands
UNEP - Energy Report Series / University of Frankfurt, Germany
Energy Report Series, ERS-13-85, Prof. K. von Gehlen, Inst. of
Geochemistry/Petroleum/Economic Geology, University of Frankfurt/Main., Germany
Notes:
Author:
Year:
Title:
Publisher:
Other Info:
[3 A]
UNEP and Technical Research Centre of Finland
1985
The Environmental Impacts of Production and Use of Energy Part IV, Phase II
Comparative Assessment of the Environmental Impacts of Energy Sources
UNEP and Technical Research Centre of Finland
Notes:
[0 M]
Author:
Year:
Title:
Publisher:
Walsh, M., OECD, Air Policy Management Group
1988
The Motor Vehicles Project: Long Term Emissions from Motor Vehicles
Organization for Economic Co-operation and Development (OECD) Environmental
Directorate, Paris, France.
Other Info:
Report Number ENV/AIR/88.13
Author:
Year:
World Health Organization
1982
[0 M]
161
Title:
Publisher:
Other Info:
Rapid Assessment of Sources of Air, Water, and Land Pollution
World Health Organization, Geneva, Switzerland
WHO Offset Publication No. 62
Notes:
This document provides a comprehensive overview of the sources of air, water, and land
pollution, including those in the energy sector. It also provides a good deal of quantitative
emissions and impacts data, though most is at a fairly generic level. This source is recommended
as a good general international reference for energy/environment planning.
[67 M]
Author:
Year:
Title:
Publisher:
Other Info:
World Health Organization
1989
Management and Control of the Environment
World Health Organization, Geneva, Switzerland
Report Number WHO/PEP/89.1
Notes:
This is an update to the above document.
Author:
Year:
Title:
Publisher:
Other Info:
Yasukawa et. al.
1990
Preliminary Analysis of Greenhouse Gas Emissions
Japan Atomic Energy Research Institute
This refers to a photocopied paper or part of a paper received by Tellus; it may have been
updated since.
Notes:
This paper provides preliminary greenhouse gas emission factors for several sectors, as well as
total emissions estimates for those sectors in Japan.
[0 M]
Authors:
Year:
Title:
Publisher:
Other Info:
Zurlinden R.A, Von Dem Fange H.P, Hahn P.E, Ogden Projects Incorporated
1986
Environmental test report for Marion County Solid Waste to Energy Facility
Ogden Martin Systems of Marion, Inc, Marion, IL, USA.
Tests were run to check compliance with permit conditions
Notes:
Provides emissions test data for a US Municipal Solid Waste Combustion/Electricity Generation
plant.
[0 M]
[8 A]
162
A Guide to Environmental Analysis For Energy Planners
163
APPENDIX B:
SUMMARY OF TABLE OF CONTENTS FROM GUIDELINE ON
AIR QUALITY MODELS (USEPA)
The text below was obtained from the USEPA "SCRAM" computer bulletin board system, and is
provided as an example listing of the type of information that is available to assist planners in selecting and
applying air quality models.
EPA-450/2-78-027R
GUIDELINE ON AIR QUALITY MODELS
(Appendix W of 40 CFR Part 51)
July 1986
(REVISED SEPT 93)
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Radiation
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
SUMMARY OF TABLE OF CONTENTS
1.0
2.0
3.0
4.0
5.0
6.0
7.0
INTRODUCTION
OVERVIEW OF MODEL USE
2.1
Suitability of Models
2.2
Classes of Models
2.3
Levels of Sophistication of Models
RECOMMENDED AIR QUALITY MODELS
3.1
Preferred Modeling Techniques
3.2
Use of Alternative Models
3.3
Availability of Supplementary Modeling Guidance
3.3.1 The Model Clearinghouse
3.3.2 Regional Meteorologists Workshops
SIMPLE-TERRAIN STATIONARY-SOURCE MODELS
MODEL USE IN COMPLEX TERRAIN
MODELS FOR OZONE, CARBON MONOXIDE AND NITROGEN DIOXIDE
OTHER MODEL REQUIREMENTS
• Fugitive Dust/Fugitive Emissions
• Particulate Matter
• Lead
• Visibility
• Good Engineering Practice Stack Height
164
8.0
9.0
10.0
11.0
12.0
13.0
14.0
A Guide to Environmental Analysis For Energy Planners
• Long Range Transport (i.e., beyond 50km)
• Modeling Guidance for Other Governmental Programs
• Air Pathway Analyses (Air Toxics and Hazardous Waste)
GENERAL MODELING CONSIDERATIONS
• Design Concentrations
• Critical Receptor Sites
• Dispersion Coefficients
• Stability Categories
• Plume Rise
• Chemical Transformation
• Gravitational Settling and Deposition
• Urban/Rural Classification
• Fumigation
• Stagnation
• Calibration of Models
MODEL INPUT DATA
ACCURACY AND UNCERTAINTY OF MODELS
REGULATORY APPLICATION OF MODELS
REFERENCES
BIBLIOGRAPHY
GLOSSARY OF TERMS
APPENDIX A: SUMMARIES OF PREFERRED AIR QUALITY MODELS
• BUOYANT LINE AND POINT SOURCE DISPERSION MODEL (BLP)
• CALINE
• CLIMATOLOGICAL DISPERSION MODEL (CDM 2.0)
• GAUSSIAN-PLUME MULTIPLE SOURCE AIR QUALITY LGORITHM (RAM)
• INDUSTRIAL SOURCE COMPLEX MODEL (ISC2)
• MULTIPLE POINT GAUSSIAN DISPERSION ALGORITHM ITH TERRAIN ADJUSTMENT
(MPTER)
• SINGLE SOURCE(CRSTER)MODEL
• URBAN AIRSHED MODEL (UAM)
• OFFSHORE AND COASTAL DISPERSION MODEL (OCD)
• EMISSIONS AND DISPERSION MODEL SYSTEM (EDMS)
• COMPLEX TERRAIN DISPERSION MODEL PLUS ALGORITHMS FOR UNSTABLE
SITUATIONS (CTDMPLUS)
APPENDIX B: SUMMARIES OF ALTERNATIVE AIR QUALITY MODELS
• AIR QUALITY DISPLAY MODEL (AQDM)
• AIR RESOURCES REGIONAL POLLUTION ASSESSMENT (ARRPA) MODEL
• APRAC-3
• COMPTER
• ERT VISIBILITY MODEL
• HIWAY-2
• INTEGRATED MODEL FOR PLUMES AND ATMOSPHERIC CHEMISTRY
• IN COMPLEX TERRAIN (IMPACT)
• LONGZ
• MARYLAND POWER PLANT SITING PROGRAM (PPSP)MODEL
165
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
MESOSCALE PUFF MODEL (MESOPUFF II
MESOSCALE TRANSPORT DIFFUSION AND DEPOSITION MODEL FOR INDUSTRIAL
SOURCES (MTDDIS)
MODELS 3141 AND 4141
MULTIMAX
MULTI-SOURCE (SCSTER) MODEL
PACIFIC GAS AND ELECTRIC PLUMES MODEL
PLMSTAR AIR QUALITY SIMULATION MODEL
PLUME VISIBILITY MODEL (PLUVUE II)
POINT, AREA, LINE SOURCE ALGORITHM (PAL-DS)
RANDOM WALK ADVECTION AND DISPERSION MODEL (RADM)
REACTIVE PLUME MODEL (RPM-II)
REGIONAL TRANSPORT MODEL (RTM-II
SHORTZ
SIMPLE LINE-SOURCE MODEL (GMLINE)
TEXAS CLIMATOLOGICAL MODEL (TCM-2)
TEXAS EPISODIC MODEL (TEM-8)
AVACTA II
SHORELINE DISPERSION MODEL (SDM)
WYNDvalley MODEL
DENSE GAS DISPERSION MODEL (DEGADIS)