Supporters of ethanol and other biofuels contend they burn cleaner than fossil fuels, reduce U.S. dependence on oil and give farmers another market to sell their produce.
But researchers at Cornell University and the University of California-Berkeley say it takes 29 percent more fossil energy to turn corn into ethanol than the amount of fuel the process produces. For switch grass, a warm weather perennial grass found in the Great Plains and eastern North America United States, it takes 45 percent more energy and for wood, 57 percent.
It takes 27 percent more energy to turn soybeans into biodiesel fuel and more than double the energy produced is needed to do the same to sunflower plants, the study found.
"Ethanol production in the United States does not benefit the nation's energy security, its agriculture, the economy, or the environment," according to the study by Cornell's David Pimentel and Berkeley's Tad Patzek. They conclude the country would be better off investing in solar, wind and hydrogen energy.
The researchers included such factors as the energy used in producing the crop, costs that were not used in other studies that supported ethanol production, said Pimentel.
The study also omitted $3 billion in state and federal government subsidies that go toward ethanol production in the United States each year, payments that mask the true costs, Pimentel said.
Ethanol producers dispute Pimentel and Patzek's findings, saying the data is outdated and doesn't take into account profits that offset costs.