Open to debate: the fuel-saving benefits of ethanol
Is it a useful alternative while other technologies ramp up? Or do its costs already exceed its potential payoff?
| 01 November 2006
Henry Ford called ethanol the "fuel of the future" and planned to run his Model T on it until oil, which was plentiful and cheap at the time, emerged as the dominant fuel. Ethanol resurfaced during the 1973 oil crisis, when gasoline prices edged upward and price controls, gas rationing, and oil embargoes became the order of the day. More recently, ethanol in a 10 percent concentration has been rapidly replacing methyl tertiary-butyl ether (MTBE) as a gasoline additive, and it is now increasingly available in an 85 percent mix called E85.
Also called grain alcohol, ethanol is one of several biofuels: fuels made from agricultural crops like corn or soybeans and waste products like used lumber and manure. The biofuel business is booming, fueled this time by more than rising prices at the pump. Proponents say biofuels could help end our dependence on oil imports, boost a sagging agriculture industry, and reduce environmental damage caused by burning fossil fuels. President Bush is advocating biofuels, Bill Gates is investing in them, and Willie Nelson is even marketing his own brand.
But not everyone agrees that biofuels are the answer to America's 20-million-barrel-a-day oil habit. Critics claim that producing biofuels consumes more energy than they generate, and some warn that converting farmland from food to fuel crops could result in higher food prices and deplete natural resources worldwide. A new campus center established this year, the Joint Center for Transportation Sustainability Research (www.its.berkeley.edu/sustainabilitycenter), will help focus Berkeley's research in the areas of transportation, environment, and sustainability, including biofuels. But for the last three years, Berkeley has been a microcosm of the ongoing debate, as two of its most widely quoted authorities, Dan Kammen and Tad Patzek, are crunching data on opposite sides of campus in an effort to determine the truth about biofuels.
(Peg Skorpinski photo)
"We know that ethanol is a net energy winner," says Kammen. "With investment and innovation, it could be a huge resource." The Class of 1935 Distinguished Professor of Energy, Kammen has appointments in nuclear engineering, the Goldman School of Public Policy, and the Energy and Resources Group. His latest research shows that corn-derived ethanol - produced from the U.S. corn crop through an expensive and resource-intensive process that uses just the corn kernel - saves significantly on gas but reduces greenhouse-gas emissions only by about 15 percent.
Even so, what Kammen likes about corn ethanol is that it is available now and can begin making a dent in our petroleum consumption while research continues on better alternatives. Most promising, he says, is cellulosic ethanol, made from paper pulp, specially designed fuel crops like switchgrass, and many wastes that can be diverted from landfill and turned into fuel. The big success story in cellulosic ethanol comes from Brazil, which will achieve energy self-sufficiency some time this year thanks to a 30-year investment in ethanol derived from its native sugar cane. Cellulosic ethanol has the potential to yield many times more energy than corn ethanol and will greatly reduce greenhouse gas emissions, Kammen says. With a few new experimental refineries under construction, he adds, cellulosic ethanol could be powering some U.S. cars in a few years.
Paying twice for ethanol
Tad Patzek, professor of civil and environmental engineering, disagrees. His studies of the amount of fossil fuel consumed in manufacturing ethanol - including everything from producing crop fertilizers and repairing farm machinery to transporting crops and building refineries - show that it takes three to six gallons of ethanol to replace one gallon of gasoline. Cellulosic ethanol performs "marginally" better than corn ethanol, he says, but will require an entirely new technology and infrastructure and is no more environmentally benign.
"Biofuels will not solve existing problems with automotive fuels," Patzek says, "but they will increase the rate at which we burn natural gas and coal while adding to CO2 emissions." Growing fuel crops of any kind strains the water supply, he adds, and is accelerating the collapse of the Midwestern-prairie-soil, tropical-forest, and savannah ecosystems through soil erosion, overuse, and land reclamation.
Biofuels would not be viable, Patzek says, without the generous federal subsidies that have cost U.S. taxpayers $144 billion in the last 10 years and end up lining the pockets of investors in agribusiness giants like Archer Daniels Midland, the leading U.S. ethanol producer. In fact, taxpayers pay twice for ethanol: first through crop subsidies to corn farmers, and again in a 51-cent subsidy on every gallon of corn-derived ethanol sold as fuel. Even worse, Patzek says, policymakers and drivers are being lulled into a sense of false comfort by what they think is the magic bullet of biofuels.
(Peg Skorpinski photo)
"We need optimism, but technology cannot 'save' us," he says. "Our lives have to be redesigned." Kammen and Patzek both advocate making aggressive investments in viable mass transit and highly efficient "plug-in" hybrid cars as well as implementing steep carbon emissions taxes. But while Kammen sees biofuels as an important part of this future scenario, Patzek says that simple gas-saving measures - like properly inflating car tires or increasing vehicle fuel efficiency by three to five miles - would reduce gas consumption more than converting to ethanol. We could do all three, Kammen counters, and reduce petroleum consumption even more.
Biofuels require specialized engines and refitted gasoline pumps, neither of which are yet in widespread use. Detroit's Big Three automakers sell several models of "flex-fuel" vehicles, capable of using either E85 or gas, and about 5 million of these can be found among the 200 million cars and trucks on U.S. roads. Of 180,000 gas stations, only about 600 can pump E85, and the oil industry estimates that it will cost owners an estimated $200,000 per station to refit their pumps. Kammen thinks that estimate is high and that the transition to ethanol will be relatively painless. But, he says, a "green fuels standard" is needed to monitor the emerging industry.
"Corn-based ethanol made at a distillery running on coal is nowhere near as good as a cellulosic ethanol plant using wind power," Kammen says, emphasizing the many options available to manufacturers. Some ethanol plants, for example, are burning coal - high in carcinogenic and greenhouse gas emissions and considered one of the world's dirtiest fuels - to save on production costs. Standards would require that plants consider sustainability as well as profit.
The United States consumes 140 billion gallons of petroleum annually, more than half of which is used for transport. If the country's entire corn crop were processed into ethanol today, it would provide enough fuel to meet only about 15 percent of those transportation needs. One thing is certain: Reducing our petroleum appetite will require a combination of aggressive research and innovation, rapid implementation of new technologies, and a dramatic change in the behavior of the American driver.
This article appears in the fall 2006 issue of Forefront, published twice yearly by the College of Engineering. Patti Meagher is the magazine's departments editor. To read the rest of the issue, visit www.coe.berkeley.edu/forefront.