A short while back I expressed a bit of skepticism about the biofuels fad. The best I could figure out was that biofuels might eventually replace up of sixth of our current supply of transport fuels. On Sunday, the Washington Post published an op/ed–"The False Hope of Biofuels"–by two Polytechnic University of New York professors that comes to an even more dour conclusion:
But allowing a net positive energy output of 30,000 British thermal units (Btu) per gallon, it would still take four gallons of ethanol from corn to equal one gallon of gasoline. The United States has 73 million acres of corn cropland. At 350 gallons per acre, the entire U.S. corn crop would make 25.5 billion gallons, equivalent to about 6.3 billion gallons of gasoline. The United States consumes 170 billion gallons of gasoline and diesel fuel annually. Thus the entire U.S. corn crop would supply only 3.7 percent of our auto and truck transport demands. Using the entire 300 million acres of U.S. cropland for corn-based ethanol production would meet about 15 percent of the demand.
Whole thing here.