REDUCING THE CARBON FOOTPRINT
IN THE AMERICAS TASK FORCE
The Center for Hemispheric Policy receives financial support from
the Bureau of Educational and Cultural Affairs of the United States
Department of State.
“Reducing the United States’ Carbon Footprint”
by
George Philippidis
Director, Alternative Energy Research Center
Associate Professor, Biofuel Engineering
University of South Florida Polytechnic (USFP)
October 10, 2011
Introduction
Carbon dioxide emissions from human activities are believed to affect the earth’s climate.
Although climate change still remains a subject of public debate in the United States, it is
becoming more widely accepted that reducing carbon emissions in rational and cost-effective
ways is a prudent step towards sustainable economic development. Minimizing our carbon
footprint should be seen as an “insurance policy” even by those who doubt the scientific
evidence of global warming.
The two most significant carbon-emitting sources in the United Sates are the power generation
sector and the transportation sector. Energy conservation measures in both electricity and fuel
use are the obvious first and most immediately-effective steps towards reducing carbon
emissions, while at the same time saving money. Beyond such measures, the prospects for the
two sectors differ, but in both cases there is reason for optimism as there are options that can be
widely implemented.
Need for Energy Policy
It is no secret that the United States has never had an energy policy that would provide a
consistent long-term vision for the nation’s energy future. Although energy demand is expected
to grow with economic expansion after the current recession, how such demand and distribution
over an aging grid system will be met remains largely undetermined. In the absence of a policy,
the country usually resorts to energy-related measures simply in reaction to geopolitical events,
such as rising oil prices resulting from conflicts in oil-producing countries. Individual states take
their own legislative action to promote energy diversification, but there is a lack of coordination
and harmonization nation-wide.
This practice leaves the U.S. vulnerable to political extortion by often hostile countries
controlling energy resources overseas. As a result, the country frequently has to expend
resources, and even human lives, to protect overseas oil fields, as happened in recent years in the
Middle East. But treating the symptoms (political instability overseas) instead of the disease
(dependency on foreign energy) will not produce energy security for the United States . The
chronic under-development of domestic energy resources has to stop right now. The United
States is rich in natural gas, biomass, wind and solar resources. With our technological
leadership, we are in a position to efficiently explore all these lower-carbon fuels, while at the
same time reducing our economy’s carbon footprint.
Power Generation Sector
As Figure 1 shows, U.S. power generation in 2010 was derived primarily from fossil resources,
with coal accounting for 45%, natural gas 23%, nuclear 20%, hydroelectric 6% and renewables
4%1. Coal is a plentiful, domestic and cheap source of energy in the United States, so it is no
surprise that almost half of our electricity comes from it. However, coal combustion is known to
be not only a carbon dioxide (CO2) emitter, but also a major source of environmental pollution
that wreaks havoc, especially on local communities where coal mining and coal use takes place.
The coal ash disaster a few years ago in Tennessee is a reminder of coal mining’s catastrophic
potential for humans and the environment.
1
U.S. Energy Information Administration, Electric Power Monthly, 2011.
2
Figure 1: U.S. electricity generation portfolio in 2010.
Although the power generation portfolio of the United States has not changed substantially for
decades, it could change over the next few years due to the vast reserves of shale gas that have
been discovered in many parts of the country that can now be accessed through hydraulic
fracturing (fracking) of the shale rock. Fracking involves the use of high-pressure hot water
mixed with sand and chemicals to blast shale rock lying several thousand feet underground,
creating fissures through which natural gas seeps upwards.
In the last ten years this technology has been widely used across the country to tap into gas
reserves that were previously inaccessible. The billions of cubic feet of gas lying underground
has led to a proliferation of exploration companies that pay landowners royalties for drilling
wells on their properties and extracting gas. As a result, fracking activity and shale gas
production have increased dramatically in the last few years.
On the positive side, natural gas is a domestic fuel with a 30% to 40% lower carbon footprint
than coal for production of the same amount of power. This means that by gradually switching
from coal-fired to gas-fired power plants over the next thirty years, the United States can
promote economic growth–through investment, tax revenue generation and jobs in the gas
sector–while at the same time shutting down polluting and aging coal-fired plants and hence
drastically reducing carbon emissions. Moreover, the ample supply of gas promises to keep
energy costs down and can even turn the country into a net exporter of gas. Given the
importance of energy security to national security, natural gas and its benefits can be a key
consideration for both politicians and the public.
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Unfortunately, as is often the case, there are also negative sides to new technologies: fracking
has environmental consequences2. Several studies and news articles document cases of water
table pollution caused by fracking operations (methane detected in drinking water), release of
radioactivity to the surface from underground and pollution by the potent chemicals used in the
fracking cocktail. Some European countries, like France, have banned the practice.3 A more
practical approach is to realize that regulation in the sector has been lax, allowing operators, in
essence, to police themselves. Consequently, several states are taking measures to regulate the
industry. This is a positive development because the United States needs domestic, cleaner and
affordable sources of energy and a clean environment at the same time.
The third major source of energy for the United States is nuclear, which currently accounts for
20% of the U.S. energy matrix. Nuclear power emits no carbon and is therefore seen, even by
environmental groups, as a means to curtail carbon emissions, while meeting increased power
demand. However, the handling of nuclear waste and the risk of accidental reactivity release still
haunt the industry. The March 2011 disaster at Japan’s Fukushima nuclear facility has
dampened enthusiasm for nuclear power around the world and may further delay deployment of
new facilities in the United States.
At 4% of the total, renewable energy sources still represent a small fraction of U.S. power
generation, but they are growing at a fast pace. Among them, wind is predominant, followed by
solar thermal and photovoltaics. In fact, wind is now among the most cost-competitive forms of
energy, even without taking into account any carbon credits, as Fig. 2 shows. Thanks to large
economies of scale (larger turbines and wind farms), wind power has dispelled the myth that
renewable energy cannot compete with fossil fuels. The same is expected to happen with solar
power. Technological advances continue to increase the efficiency and reduce the cost of solar
cells. When such developments are coupled with larger economies of scale, solar power is also
expected to grow significantly over the next decade. Both solar and wind are domestic sources
of power and emit no carbon, while at the same time providing opportunities for research and
development (R&D) innovation, investment and employment.
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3
“The Facts About Fracking”, The Wall Street Journal, June 25, 2011.
“France to ban fracking of fossil fuels”, Financial Times, May 11, 2011.
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10
5
0
Coal
Gas
Nuclear
Wind
Figure 2: U.S. baseload power generation cost in 2005 cents per kilowatt hour (kWh).
The downside of wind and solar is their intermittent nature, which prevents them from
contributing to the base-load needs of the grid. As a result, they currently address only peak
demand, but as energy storage systems (such as batteries) become more cost-effective, these
forms of renewable energy are destined to play an increasingly important role in zero-carbon
power generation.
Another no-carbon national resource that has not yet been adequately explored is biomass.
Biomass is any kind of plant material that is produced via photosynthesis. Although combustion
of biomass for power generation releases CO2, through the natural carbon cycle this carbon
dioxide is re-absorbed from the atmosphere to photosynthetically produce more biomass, hence
power from biomass is renewable. Every year the U.S. generates significant amounts of
cellulosic biomass in various forms, depending on local climate and ecology, including
agricultural residues, such as corn stover, wheat straw and sugarcane bagasse; woody residues
from forest management; yard waste from residential and commercial properties; and grasses and
energy crops.
Moreover, new technologies promise to enhance the energy efficiency of biomass. For example,
gasification systems have been shown to improve the conversion of biomass to power, while
torrefaction, a pre-treatment technology, allows conversion of green biomass to an energy-denser
biocoal, which can supplement (co-firing) or replace coal as a fuel. A Department of Energy
(DOE) and United States Department of Agriculture (USDA) study in 2006 estimated that
annually, almost a billion tons of biomass are generated in the United States4. Tapping into this
abundant source of fuel can contribute to our low- and no-carbon power generation capacity.
“Biomass as Feedstock for a Bioenergy and Bioproducts Industry: The Technical Feasibility of a Billion-Ton Annual Supply”, Oak Ridge
National Lab, 2005.
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Transportation Sector
In 2010, the United States consumed 136 billion gallons of gasoline and 45 billion gallons of
diesel, both derived mainly from imported oil. Unlike power generation, where domestic energy
sources (albeit highly polluting, such as coal) are utilized, the U.S. transportation sector depends
on oil imported from the Organization of Petroleum Exporting Countries (OPEC) and other
countries, some of which are openly hostile to U.S. interests, for more than 65% of its needs.
Clearly the current status quo makes no political, geopolitical or financial sense. Yet, there is no
federal policy to move us away from our dependence on oil, since alternatives to oil products,
such as biofuels, have long been ignored and only in the last few years have received attention.
Even now that alternative and renewable fuels are being seriously considered, wasteful farm
subsidies are being employed instead of growth incentives for the renewable fuels industry.
Thanks primarily to state mandates, corn-based ethanol today represents almost 10% of the
transportation fuel used in the country. The 13 billion gallons of ethanol consumed annually by
U.S. motorists come from corn produced in Midwestern states that receive a $0.45 per gallon
government subsidy to make corn ethanol cost competitive. Moreover, a $0.54/gal tariff is
imposed on imported Brazilian ethanol produced from sugar cane. Cane ethanol is produced in
Brazil at a significantly lower cost than corn ethanol produced in the United States and would
greatly benefit U.S. consumers, if it were allowed to be imported into the country without the
tariff. As a result of the corn ethanol subsidy, the U.S. taxpayer spends over $5 billion a year,
the single largest agricultural subsidy, to support the corn ethanol industry. In essence, this is not
a biofuels subsidy, but rather a farm subsidy in the name of biofuels and energy security.
Unfortunately, even the carbon footprint of corn ethanol is not necessarily smaller than that of
gasoline, as seen in Fig. 3. This is due to the fact that ethanol production from corn in the United
States relies heavily on the use of a fossil fuel (natural gas) to satisfy the high-energy needs of
corn-ethanol plants, mainly for distillation purposes. As a result, although the product (ethanol)
is renewable, on a life-cycle basis its production results in significant carbon emissions.
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100%
90%
80%
70%
60%
GHG Emissions 50%
40%
30%
20%
10%
0%
Gasoline
Corn
Sugar beet
Wheat
Cellulosic Sugarcane
Figure 3: Greenhouse gas (GHG) emissions when using ethanol produced from various sources, as
compared to gasoline, calculated on a life-cycle basis.
In contrast, sugarcane ethanol enjoys an almost 90% carbon emissions reduction compared to
gasoline, because sugarcane-ethanol plants utilize their own bagasse (biomass leftover from
sugarcane) to power themselves. As explained earlier, biomass is carbon neutral, hence
sugarcane ethanol is produced more cost-effectively than corn ethanol and results in a lower
carbon footprint than both gasoline and corn ethanol. In fact, thanks to technological
advancements over the last 40 years in the cultivation of sugarcane and the fermentation of
sugars, Brazilian ethanol is competitive with gasoline at oil prices as low as about $60 per barrel.
Recently, the U.S. Senate voted to repeal the corn ethanol subsidy, but the issue is so politically
charged that it is impossible to predict what the fate of the subsidy will eventually be. Increased
use of cheaper sugarcane ethanol will make a strong contribution to reducing the carbon footprint
of the U.S. transportation sector and will result in lower energy costs for U.S. drivers.
The U.S. government has set an ambitious annual production goal of 36 billion gallons of
biofuels by 2022, recognizing that only 15 billion gallons of ethanol can realistically be produced
from corn. As the U.S. corn-ethanol industry has already reached the 13 billion-gallon level,
biofuels from other resources are actively being developed by a new cadre of companies
investing heavily in advanced biofuels, which are derived from non-edible biomass resources
rather than from corn. As a result, such biofuels are not part of the “food vs. fuel” controversy
and are therefore considered sustainable. As Fig. 3 shows, the carbon footprint of cellulosic
ethanol is projected to be at least 80% lower than that of gasoline. It, therefore, represents a
major tool for lowering carbon emissions from our transportation sector.
The conversion of biomass to biofuels has been the subject of intense R&D work and public and
private investment over the last 10 years due to the ample availability of low-cost biomass in the
United States. Companies, mostly funded by venture capital, have developed biochemical and
thermochemical processes to convert biomass to a variety of liquid fuels, such as ethanol,
butanol, diesel and hydrocarbons.
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Some of those technologies are currently in the demonstration phase and are expected to be
deployed soon on a small commercial scale. Biochemical technologies utilize enzymes to break
down biomass to sugars, which are subsequently fermented by microorganisms to biofuels.
Thermochemical technologies gasify biomass to a mix of methane and carbon dioxide (syngas),
which is then catalytically converted to a mix of hydrocarbons or alcohols.
In the last five years, another promising source of alternative fuels has been developed–algae.
Because algae require CO2 to grow, algal fuels are projected to have a low-carbon footprint.
Algae have the advantage of growing much faster than cellulosic biomass, but processing and
production of fuels still entail engineering challenges. Algae-derived lipids form the basis for
the production of hydrocarbons for aviation and military use, as well as of biodiesel for vehicles.
At the same time, there are additional options to drive carbon emissions even lower: electric
vehicles and natural gas-powered vehicles. A new generation of electric vehicles has already
been introduced into the marketplace. Some are electric-gasoline hybrids, whereas others are
pure electric cars operated solely with a battery. Although an electric vehicle per se emits no
CO2, its contribution to a lower carbon footprint depends on how the electricity it uses is
produced. Hence, the question rolls back to the power generation sector, where renewable
sources and natural gas represent preferable fuel sources.
The issue of natural gas vehicles has resurfaced again with the discovery of large reserves of
shale gas in the United States. Hence, gas can play a dual role: generate electricity and power
vehicles. The latter will obviously require modifications to existing vehicles and fuel stations,
which will require a significant investment. The lack of an energy policy will certainly not help
investors interested in pursuing such opportunities.
We may see true flex-fuel vehicles (able to operate on multiple fuels and blends) being produced
a few years from now, as is the case in Brazil, where drivers can utilize biofuels or gasoline or
blends of the two or natural gas, depending on the daily price of each fuel. With an energy
policy in place supporting the development of alternative and renewable low-carbon fuels, U.S.
consumers themselves will have the choice (many fuels) and means (flex vehicles) to reduce
their own carbon footprint on a daily basis and without senseless and costly subsidies.
Furthermore, in addition to investors promoting renewable and alternative fuels, oil companies
have started participating in clean technology ventures ranging from electric vehicles to
cellulosic biofuels and algae. Finally, polls indicate that the U.S. public supports efforts to
reduce the country’s carbon footprint through energy conservation (both power and fuel) and
recycling5.
Conclusion
There are tremendous opportunities in the United States to advance economic growth by
investing in low-carbon energy technologies, which will spur job creation, increase tax revenues
5
ABC News-Planet Green-Stanford University poll as reported on August 9, 2008 at abcnews.go.com.
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and reduce the carbon footprint in the United States, as well as place the entire U.S. economy on
a more sustainable footing. In power generation, shale gas represents an opportunity to displace
polluting coal, while solar, wind and biomass are additional plentiful natural resources that can
be tapped and are cost-competitive if used on a large scale. In the transportation sector, biofuels
from biomass and algae can enhance U.S. energy security by reducing oil imports. Electric cars,
particularly in combination with cleaner electricity produced from natural gas, and even naturalgas vehicles, could complement alternative fuels in order to truly diversify the U.S. energy
portfolio.
At the federal level, the U.S. government needs to develop a long-term, bipartisan roadmap
towards energy security by investing in domestic, clean-energy resources. The private sector
eagerly awaits such a policy, so it can invest with confidence in the country’s future. To develop
new low-carbon energy sources there is no need for wasteful subsidies and import tariffs, or for
the government to pick “winners and losers.” Instead, government support should be granted in
the form of loan guarantees to help the private sector commercialize new technologies and build
the solar, wind, biomass, biofuels and natural gas facilities needed to break this country’s coal
and oil energy dependence. Public-private partnerships will benefit the U.S. consumer directly
and secure the country’s energy future in a sustainable way.
_____________________________
Dr. George Philippidis is director of the Alternative Energy Research Center and associate professor of biofuel
engineering at the University of South Florida Polytechnic at Lakeland, Florida, in the Tampa Bay area. He is an
international expert in the biofuels and renewable energy business with experience in both the private and public
sectors.
All statements of fact or expression of opinion contained in this publication are the responsibility of the authors.
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