Ethanol as Alternative Fuel: Benefits, Costs, and Trade-Offs

Introduction: Energy Dependency and the Search for Alternatives

More than ever, Americans are growing concerned about alternative fuels, driven by the possibility of global warming, significant increases in gasoline prices for automobiles and other vehicles, and a broader shift toward environmental awareness. Deciding which alternative fuels to use — for automobiles, for example — is not easy. There are a number of known factors to consider, as well as many unknowns. One of the alternatives receiving considerable attention is ethanol. Like other options, however, it has both advantages and disadvantages.

The United States depends on foreign producers for more than half of the oil it consumes. Concerns about energy dependency have only grown in recent years, with reliance rising from 35 percent in the 1970s to 56 percent in 2000. One possibility is to increase domestic oil production; however, this could seriously harm the environment, and the country's oil reserves are finite. All other solutions for obtaining oil still ultimately rely on a nonrenewable energy source. Resource experts say that readily available natural petroleum will be nearly exhausted within about three decades. By 2050, conventional petroleum production may fall by as much as 75 percent from its current peak. In addition, global warming will continue regardless of whether an alternative fuel is found; however, this trend can be slowed through positive action (Cothran 14–16).

Ethanol Overview: Forms, Production, and Policy

Admittedly, some specialists do not agree with this scenario and argue that dramatic restrictions on fossil-fuel energy use would drastically alter economic stability and growth. They warn that many nations have not signed the Kyoto Protocol to cut CO2 emissions and that imposing strict energy restrictions risks economic collapse. According to Michael Fox, a science analyst for the Grassroot Institute of Hawaii and a retired chemistry professor, "Increasing the costs of energy, strangling the use of our energy sources (coal, oil, nuclear, and hydro) will most assuredly" result in economic collapse (Hawaii Reporter). Until a viable long-term solution is readily available, he argues, changing standards is premature.

Regardless of which position one holds, fuel alternatives will eventually be necessary, and it is prudent to examine the options and weigh their advantages and disadvantages. One of the major alternatives being proposed is biofuels or biomass, especially ethanol. Biofuels are derived from organic matter — such as corn stalks — that can be converted into energy. Many oil companies in the U.S. already use a mixture of biofuels and oil for home heating, and approximately 30 percent of all gasoline consumed in the U.S. is blended with ethanol (U.S. Department of Energy). Biomass fuel is a renewable energy source that, unlike fossil fuels, is inexhaustible and less harmful to the environment. Legislation currently under consideration in Congress includes measures to reform fuel-economy standards and boost biofuel production.

Proponents note that ethanol is a clear liquid with an agreeable odor that can be made from natural products and is blended with gasoline to provide a cleaner, more natural fuel source. It is a renewable fuel because it is made from plants. Ethanol comes in three forms: E95, or near-pure ethanol, which normally cannot be used alone and is added to gasoline; E85, considered the best alternative form, which consists of 85 percent ethanol and 15 percent gasoline; and E10, which combines 10 percent ethanol and 90 percent gasoline and is currently the most widely used blend (U.S. Department of Energy). A central question about biofuel use is whether it would actually free the country from a petroleum economy. Producing ethanol requires considerable energy and could divert corn and soybeans from the nation's food supply. These energy-balance and environmental concerns have fueled strong debate among scientists, legislators, and environmental groups.

The Net Energy Balance Debate

In a speech entitled "Reducing Greenhouse Gases," Bob Dinneen, president of the Renewable Fuels Association, noted that 2006 was a pivotal year in the history of the ethanol industry, due to increased public awareness and tremendous growth in ethanol production. By mid-year, MTBE had been replaced by ethanol nearly wherever reformulated gasoline was available. The U.S. ethanol industry produced 4.9 billion gallons, sold over 5.5 billion gallons, developed new biorefineries, and ended the year with over 5.4 billion gallons of production capacity.

Yet there is, as Jozefowicz notes (6), "a hitch" to ethanol: it takes energy to make energy. Gasoline has a positive net energy ratio — it takes approximately 20 percent additional energy to produce one gallon of gasoline from oil compared to the energy that gallon contains. By contrast, many studies cited by Alex Farrell, a researcher in energy management at the University of California, Berkeley, indicate that ethanol has a negative net energy cost — meaning that less energy is required to produce one gallon of ethanol from corn than that gallon actually contains. However, not all scientists agree. David Pimentel, a professor of agriculture and ecology at Cornell University, argues that ethanol actually has a positive energy cost — even higher than that of gasoline. He and his colleague Tad Patzek calculated that producing ethanol requires nearly 30 percent more energy than it yields, most of which goes into running farm equipment and production facilities.

The organization Ethanol Across America contends, in their brief "Net Energy Balance of Ethanol Production," that this confusion arises because analysts are not comparing equivalent quantities. Those who find ethanol inferior often compare the BTU content of one gallon of ethanol directly to that of gasoline, or evaluate the energy expended in production, and stop there. The brief argues, however, that "the reality is that it is far from straightforward, and comparisons based on raw numbers from an era of cheap energy are indeed comparing apples to oranges." Instead, the brief points to a statistical analysis conducted by the U.S. Department of Agriculture using the Aspen Plus model, which estimates the thermal and electrical energy used in each phase of ethanol and co-product production — including steeping, milling, liquefaction, saccharification, fermentation, distillation, and drying. The Aspen Plus results concluded that about 65 percent of total energy used in an ethanol plant is attributable to the ethanol itself and 35 percent to by-products. The brief characterizes this as "a simple and straightforward means of finally looking at this issue," adding that "the picture improves as evidenced by the new USDA finding."

Conclusion: Proceeding With Caution

Ethanol can be a positive alternative to the country's heavy reliance on foreign fossil fuels, as well as a partial response to global warming. However, history shows that humans tend to wait until a problem becomes severe and then move full speed ahead without examining all the ramifications. In most cases, those who raise concerns about ethanol are not saying "don't consider it at all." They are saying: look carefully at this alternative, compare it to others, and assess the impact it will have on other sectors of society and the environment. It appears that the energy crisis will not be solved by a single silver bullet. A combination of approaches will be required, of which ethanol may be one component. Although the ethanol industry is built on the hope of creating a sustainable, renewable energy source, it is equally necessary to examine the potential negative effects of high corn consumption and rapid, large-scale production expansion.

Bies, Laura. "The Biofuels Explosion." Wildlife Society Bulletin 34.4 (2006): 1203–1206.

Cothran, Helen. Energy Alternatives. San Diego: Greenhaven Press, 2002.

Dinneen, Bob. "Reducing Greenhouse Gases." Vital Speeches of the Day 73.4 (2007): 167–171.

Ethanol Across America. 18 July 2007.

Jozefowicz, Chris. "Fuel for Thought." Current Science 92.11 (2007): 6–8.

Nature Biotechnology. "Bioethanol Needs Biotech Now." 24.7 (2006): 725.

Sakr, Youmna. "The Fight between Fuel and Food." Risk Management 54.4 (2007): 64–68.

U.S. Department of Energy. 18 July 2007. http://www.energy.gov/