Wisconsin Public Utility Institute
October 3, 2011
Natural Gas: How Does it
Compare?
Peter Taglia, P.G., Environmental Geologist and Consultant
Outline
•
Drilling for Natural Gas has Impacts…. But On What
Basis Should We Compare Different Energy
Resources?
Lifecycle Analysis for water, air pollution, GHGs
− Comparison with Realistic Alternatives
− Compatibility with Current and Developing Clean
Energy Sources
−
•
•
Wisconsin’s Current Energy Mix
Coal and Natural Gas Comparison
Electric Sector
− Transportation Sector
−
Producing and Consuming Energy Have
Impacts…. There’s No Free Lunch
•
The Manufacture
and Use of All
Energy
Conversion
Devices, Including
Wind and Solar,
Produce Human
and
Environmental
Health Impacts
Bat Killed By Wind Farm, Silica Mining and Manufacture Hazards Applicable to Solar
Panels, Large Iron Ore Mine in Michigan – Possible Source of Steel for Wind Towers
Sources: Ana Jančar, WikiCommons, OSHA,
http://www.geo.msu.edu/geogmich/images/empire_iron_mine2.JPEG
Lifecycle Analysis: Energy
•
A Reasoned
Comparison of
Environmental
Impacts Looks at
the Full Lifecycle
of a Resource
•
Wind Turbine
Example Based on
Energy
•
Time Scales Are
Important
Energy Return On Investment (EROI)
Example
http://www.eoearth.org/article/Energy_return_on_investme
nt_(EROI)_for_wind_energy
Lifecycle Analysis: Health
•
In Addition to Energy
Consumed, Health
Impacts Can be Compared
For Different Energy
Resources
•
The Impacts Must Be
Compared to the Energy
Produced
•
One Terawatthour (TWh) =
Annual energy production
from 24/7 Operation of a
114 MW Power Plant, OR,
Calculations of the Health Impacts of Various
approximate annual
Forms of Electricity Generation in the EU
electrical energy used by
Source: http://manhaz.cyf.gov.pl/manhaz/strona_konferencja_EAE-2001/15%20-%20Polenp~1.pdf
about 100,000 U.S.
households
Lifecycle Analysis: Who Do You
Trust?
•
Lifecycle Analysis (LCA)
is an Emerging Science
•
What are the Boundaries
of the Analysis? Is the
Food Consumed by a
Miner/Driller Included?
The Emissions to Produce
the Excavator or Drill
Rig?
•
Transparency and PeerReview Help Narrow the
Numbers
Lifecycle Greenhouse Gas (GHG) Results for
Various Fuels Using Different LCAs
http://www.midwesterngovernors.org/Publications/LCFPagDoc.pdf
Back to Natural Gas: What are
the Alternatives?
•
Or, if we stopped all
natural gas production,
would the environment
be better or worse?
•
What are the
alternatives?
•
How does this vary by
region?
•
How much time is
needed to deploy
cleaner resources?
Hobet Coal Mine (W.Va) in 1984 (top) and 2009
(middle), Valley Fill, Martin Co, KY (bottom)
Source: NASA Landsat Image, mountainroadshow.com
Wisconsin’s Energy Mix by Fuel
•
•
•
#1 Coal is used
primarily for electrical
generation (90%)
#2 Petroleum is used
primarily for
transportation (83%)
#3 Natural gas
consumption is divided
between residential,
industrial, commercial,
and electrical
generation uses
Wisconsin Energy Use by Fuel
Source: WI State Energy Office, 2010
Electric Sector:
Natural Gas Versus Coal
Electrical Generation in WI by Fuel
•
•
Coal provides
approximately 70% of
WI electrical sales (instate generation and
imports)
But, Wisconsin has
2,400 MW of highly
efficient natural gas
generation operating
below capacity that
could offset coal
Coal
60%
COAL
2009 Electrical Generation in WI
Source: WI PSC, SEA 2011
Coal and Public Health in WI
•
According to an extensive peer-reviewed study by the National Research Council of
the National Academies of Sciences that was published in October 2009, the hidden
costs of coal far exceed the costs of renewable energy, natural gas and nuclear energy.
http://www8.nationalacademies.org/onpinews/newsitem.aspx?RecordID=12794
•
“In 2005 the total annual external damages from sulfur dioxide, nitrogen oxides, and
particulate matter created by burning coal at 406 coal-fired power plants, which
produce 95 percent of the nation's coal-generated electricity, were about $62 billion;
these nonclimate damages average about 3.2 cents for every kilowatt-hour (kwh) of
energy produced.”
•
For WI these health impacts add up to about $1.5 BILLION per year based on the
approx. 45 billion kWh of electricity generated from coal in WI.
•
In contrast, the study found that “Burning natural gas generated far less damage than
coal, both overall and per kilowatt-hour of electricity generated. A sample of 498
natural gas fueled plants, which accounted for 71 percent of gas-generated electricity,
produced $740 million in total nonclimate damages in 2005, an average of 0.16 cents
per kwh.”
Coal and Public Health – New Plants
•
•
•
•
•
•
Health Impacts of the
New Supercritical Coal
Plants in Oak Creek, WI:
26 premature deaths
2,000 asthma attacks
350 emergency room
visits
26,000 minor restricted
activity days
$188 million in public
health impacts
•
Source: Harvard School of Public Health, 2003
testimony to Wisconsin PSC
Mercury in Wisconsin
•
Coal is responsible for 86% of
Wisconsin’s mercury emissions
(http://dnr.wi.gov/air/pdf/HG-FactsheetOnAdoptedRuleFINALREV8-08Jon.pdf)
•
To avoid mercury, a potent
neurotoxin, consumers must
consult a statewide fish
consumption advisory
Source: Wisconsin DNR
How Do Individual Coal and
Natural Gas Power Plants
Compare?
Pounds of CO2e per MWh
DIRECT Greenhouse Gas (GHG) Emission Comparison
Fossil Power Plants
2500
2000
1500
1000
500
0
Sources: NETL, Cost and Performance Baseline for Fossil Energy Plants (Rev. 1), August 2007 (SCPC, IGCC,
NGCC and IGCC w/CCS), WI PSC 2008 WPL FEIS (SubPC and CFB, normalized to NETL emission data
based on heat rate and N20 emissions). Note: Emission rates are for rated output under ISO conditions, actual
emissions can be higher.
Full Lifecycle GHG Emissions
•
In addition to the direct
(smokestack) emissions,
coal and natural gas result
in upstream emissions
−
−
−
Construction
Transportation
Mining
•
Fugitive emissions of
natural gas (a greenhouse
gas) result in higher
upstream emissions
•
Current research (e.g.,
Howarth, 2011) is debating
the fugitive emissions of
natural gas on a BTU (not
delivered energy) basis
Coal
Natural
Gas
Source: National Renewable Energy Lab, NREL/TP-510-32575 , Pamela Spath and Margaret Mann, 2004
Power Plant Typical Emissions by Technology Type
0.5
0.45
0.41
0.4
NOx
lb/MMBtu
0.35
SO2
0.31
0.3
Particulates
0.25
0.2
0.17
0.165
0.15
0.15
0.1
0.085
0.057 0.053
0.05
0.027
0.02
0.018
0.007
0.019 0.013
0.004
0.015
0.002 0.01
0
Traditional PC
Retrofit Older PC's
w/Scrubbers & SCR
(using low-S Coal)
Advanced
PC/SCPC/CFB
IGCC
w/MDEA Absorber
IGCC
w/Rectisol & SCR
NGCC w/SCR
Type of Power Plant
Source: Clean Air Task Force 2007. Note: Comparison based on fuel input in Btu’s, not output (e.g.,
MWh), thus actual emissions are lower per MWh for the more efficient plants (e.g., NGCC).
Water Consumption Comparison
1,200
Water Withdrawal
Water Consumption
1,000
600
906
400
415
334
375
358
179
269
200
267
593
705
Water (gal/MWh)
800
0
Nuclear
NGCC
IGCC (Shell)
IGCC (GE)
SCPC
Source Data: NETL 2007, EPRI 2002
Natural Gas and Intermittent
Renewables
•
•
High penetration of wind and
solar will require a more
flexible grid
Current natural gas power
plants have a much greater
capacity to balance
fluctuations in wind and solar
output than coal or nuclear
−
•
Example: Fox Energy Center
in WI can ramp up/down at
15 MW per minute
The newest designs can ramp
up and down as much as 50
MW per minute at electrical
efficiencies of greater than
50%
Fox Energy Center (470 MW) Kaukauna WI (TOP),
General Electric’s FlexEfficiency Natural Gas Combined
Cycle Power Plant (Bottom) Sources: Boldt, GE
How Do Petroleum and
Natural Gas Compare in the
Transportation Sector?
Wisconsin’s Petroleum: Heavy Crude
and Getting Heavier
•
Producing Fuel from Canadian
Oil/Tar Sands Requires Massive
Mines, Large Energy Inputs and
Toxic Tailing Ponds
Oil Pipelines, Athabasca Oil Sands, Open Pit
Oil Sands Mine
Sources: EIA, NASA, ANL
The Midwest’s Oil Supply
OPEC
108,682
(18%)
Other
19,328
(3%)
Canada
476,860
(79%)
Conven
tional
53%
Oil
Sands
47%
Midwest Oil Imports (Left) Canadian Imports by Resource (Right)
Source: EIA imports for PADD2 (2009) and Canadian National Energy Board (2009)
http://www.neb.gc.ca/clf-nsi/rnrgynfmtn/sttstc/crdlndptrlmprdct/crdlndptrlmprdct-eng.html
Transportation Fuel Lifecycle Comparison
Transportation Fuel Lifecycle
Assessment
Source: Argonne National Lab
The Carbon Footprint of Oil Sands
•
Gasoline and
Diesel
produced from
the oil sands
have a full
lifecycle carbon
footprint
approximately
15% greater
than
conventional
sources
http://www.midwesterngovernors.org/Publications/LCFPagDoc.pdf
Carbon Intensity (grams/Megajoule)
Lifecycle Carbon Footprint Comparison
120
100
80
60
40
20
Example Carbon Intensities for Various Fuels
Electricity (100%
Coal)
Woody Biomass
Ethanol (Gasification)
Oil Sand Gasoline
Compressed Natural
Gas
Soy Biodiesel
Corn Ethanol
Gasoline
(Reformulated)
0
Source: From Table 3-10 of the report “Introducing a Low Carbon Fuel Standard in the Northeast” by the Northeast States Center for a Clean Air
Future (NESCCAF), July 2009. http://www.nescaum.org/documents/lcfs-report-final.pdf and an electricity conversion factor of 4
Natural Gas Burns Dramatically
Cleaner in Vehicles
The Honda Civic GX has been named the “World’s
Cleanest Internal Combustion Vehicle” by the
USEPA
According to the USEPA, compressed natural gas results in:
•Reductions in carbon monoxide emissions of 90 to 97 percent
•Reductions in nitrogen oxide emissions of 35 to 60 percent
•Potential reductions in nonmethane hydrocarbon emissions of 50 to 75 percent
•Fewer toxic and carcinogenic pollutants, and little to no particulate matter produced
•No evaporative emissions in dedicated engines (such as those associated with
gasoline or diesel)
Renewable Natural Gas: A Cleaner
Natural Gas Future?
•High Efficiency Natural Gas
Applications Do Not Have To Be
Fossil-Fueled
•Renewable Natural Gas is
Produced by the Anaerobic
Digestion of Organic Wastes
(Manure, Food Waste, Wastewater
Treatment)
•Wisconsin Leads the U.S. in
Farm-Based Anaerobic Digestion
•Small but Growing Resource
Anaerobic Digester and Canadian Natural Gas
Utility Offering Renewable Natural Gas
Thank You
Peter Taglia
[email protected]
Extra Slides
Cross-Sector Comparison: Electric
Water Heating
•Electric resistance water
heaters are around 90%
efficient at converting
electrical energy into hot
water…. BUT
•Converting heat into
electricity at a power
plant, and transmitting
that energy to the house,
conserves only about 33%
of the original energy
•Thus, for every unit of
energy burned to create
electricity, only approx.
0.3 units of hot water is
produced
Cross-Sector Comparison: Natural
Gas Water Heating
• Conventional Natural
Gas Water Heaters are
Approximately 60%
efficient at converting fuel
into hot water
•Tankless natural gas
water heaters are
approximately 80%
efficient
•Tankless, condensing,
natural gas water heaters
are up to 98% efficient
Cross-Sector Comparison: Water
Heating
• 26% of Wisconsin’s Water Heaters
are Electric
• Incentives are still offered for
conventional resistance electric water
heaters
• Converting electric water heaters to
natural gas would save approximately
3.1 Metric Tons of CO2 per Year.
•Source: Page 101 WI Task Force on Global
Warming
http://dnr.wi.gov/environmentprotect/gtfgw/docu
ments/Final_Report.pdf
GHG Emissions in Wisconsin
•
•
•
WI’s GHG emissions
were 123 Million Metric
Tons (MT) CO2e in 2003
− 14% higher than
1990
Electrical generation is
the largest source of
GHGs in WI
− 43 MT CO2e
− 30% higher than
1990
Transportation
emissions second, and Wisconsin Greenhouse Gas Emissions by Sector
Source: World Resources Institute, Charting the Midwest, 2007
rising