Could gasoline be more green than biofuels, the farm-grown darlings of Iowa farmers and Willie Nelson?
The counterintuitive, provocative question has been posed by several University of Texas researchers in a pair of recent papers that look at how much water is required to produce fuels such as gasoline and ethanol.
The papers underscore the trade-offs at play as the United States plots its energy future.
An analysis by the researchers, postdoctoral fellow Carey King and mechanical engineering professor Michael Webber, shows that the entire biofuel production cycle — from growing irrigated crops to pumping biofuel into a car — can consume 20 or more times as much water for every mile traveled than is used in the production of gasoline.
"We're trading off foreign oil for domestic water," Webber said in an interview. Webber is also associate director of UT's Center for International Energy and Environmental Policy.
Biofuels make up only a fraction of the fuel at the pump and the federal government has locked in subsidies to encourage biofuel production. Under a current mandate, at least 7.5 billion gallons of renewable fuel must be blended into motor-vehicle fuel sold in America by 2012. By 2030, Americans are set to get about 15 billion gallons a year from biofuels.
Water consumption by light-duty vehicles, in turn, will increase from 1.4 trillion gallons a year in 2005 to nearly 2.7 trillion gallons in 2030, according to a second paper written by King and Webber, along with Bureau of Economic Geology associate director Ian Duncan. The paper was presented in August at the International Conference on Energy Sustainability, organized by the American Society of Mechanical Engineers.
The water demanded by biofuel crops could force cities and states, especially in the Midwest, to make tough choices about their water future. Two years ago, for example, Champaign, Ill., balked at a proposal for a plant that would produce 110 million gallons of ethanol a year, requiring 2½ gallons of water for every gallon of ethanol produced.
The city required the company that wanted to build the plant to place monitoring wells around the property to make sure neighbors were not "negatively impacted," according to Teri Legner, economic development manager of the City of Champaign. The plant has not been built.
The water issue is another chapter in the biofuel story. Biofuels such as ethanol promised energy independence, a boost for farmers, and low carbon dioxide emissions, winning the adulation of Iowa politicians and popular icons such as singer Willie Nelson, who lends his
name to the biodiesel company BioWillie.
Texas has an ethanol production incentive of 20 cents a gallon, and there are at least nine ethanol plants built or under construction in the state.
The state energy conservation office says that it does not track water requirements for ethanol production.
But in the past couple of years, biofuels have been hammered by some scientists, some of whom argue that it takes more energy to produce ethanol from corn than ethanol can create. Others say the land used to grow biofuel crops should be given over to food crops.
The University of Texas analysis calculates the water use in farming and processing of the fuel. It doesn't take into account its transportation to the fuel pump.
"By increasing the link between agriculture for biofuels and transportation, the U.S. is inherently increasing the link between water consumption and driving habits," according to the paper.
"For the United States, the benefits of domestically sourced biofuels and electricity (from coal and hydropower) must be weighed against potentially negative environmental impacts," it says.
A National Academy of Sciences report titled "Water Implications of Biofuels Production in the United States," published last year, raised similar questions. It said fertilizers used to increase agricultural yields could lead to nitrogen and other nutrients flowing into the nation's rivers and creating oxygen-starved "dead zones."
"Significant acceleration of biofuels production could cause much greater water quantity problems depending on where the crops are grown," according to the report. "Growing biofuel crops in areas requiring additional irrigation water from already depleted aquifers is a major concern."
But Jim Kleinschmit, director of the rural communities program at the Minnesota-based Institute for Agriculture and Trade Policy, said ethanol production is slimming down its water consumption as the production process is refined. He said a crucial aspect of making biofuels sustainable is the planting of crops appropriate for wet and arid climates.
"We encourage growing appropriate crops that are not water intensive," he said.
More than 90 percent of corn grown in the U.S. is dryland production, in which no supplemental water is used, said David Gibson, executive vice president of the Corn Producers Association of Texas.
"Primarily the corn grown in the U.S. is done with natural rainfall and without irrigation," he said.
Gibson said that 60 percent of corn grown in Texas, however, is dryland production. Much of the irrigated corn takes root in the Panhandle.
Texas has sent mixed signals on biofuel production.
In April, Gov. Rick Perry asked the federal government to cut by half the amount of corn-based ethanol that must be blended into the national fuel supply under the national renewable fuel standard. In a move supported by ranchers who have seen their feed prices skyrocket, Perry said the corn should be used as food for livestock and people.
The federal Environmental Protection Agency rejected the request.
But Texas continues to lend support to farmers who grow crops for biofuels.
"Science and research will lead the way toward the most efficient uses of our natural resources for the development of alternative energy," Texas Agriculture Commissioner Todd Staples said. "Agricultural producers understand the balance needed between water usage and productivity. I am confident, as markets develop and through technological advances, sustainable biofuel production can have a positive impact on our national energy needs.
"National security is dependent upon energy security," Staples said, "and developing a diversified fuel base is critical to our economic strength and vitality."
asherprice@statesman.com; 445-3643
