Ethanol produces more energy than it takes to produce, says U.S. analysis

ARGONNE, Illinois, US, April 20, 2005 (Refocus Weekly) Ethanol generates 35% more energy than it takes to produce, due to the use of solar energy to grow the corn, according to a study by Argonne National Laboratory.

“We believe (the study) has laid to rest some long-held misunderstandings about ethanol and its important role in reducing America's reliance on imported oil and our greenhouse gas emissions,” the U.S. Department of Energy concludes in a study by researcher Michael Wang. “In terms of key energy and environmental benefits, cornstarch ethanol comes out clearly ahead of petroleum-based fuels."

DOE’s Office of Energy Efficiency & Renewable Energy says the study should help quell debate about the net energy balance of ethanol, and will reinforce that production of the corn-based fuel yields a net energy gain. Earlier research by the U.S. Department of Agriculture, Michigan State University, Colorado School of Mines, Institute for Local Self-Reliance and others concluded that ethanol has a positive net energy balance, and a USDA study in 2004 found that ethanol may net as much as 67% more energy than it takes to produce.

In the last ten years, only two studies (both conducted by Cornell University entomologist David Pimentel) have found the net energy balance of ethanol to be negative.

“Some of the confusion arises over the fact that some of the total energy used in the production of ethanol is 'free' solar energy used to grow the corn in the first place,” the report notes. “Since the solar energy is free, renewable and environmentally benign, we shouldn't care.”

Ethanol also has a positive benefit in the reduction of greenhouse gas emissions, Wang found, with corn ethanol reducing GHG emissions by 18% to 29% on a per-gallon basis.

The United States consumes 3 billion gallons of fuel ethanol a year, second to Brazil, with most produced from corn and most blended with gasoline. Congress is considering legislation to increase fuel ethanol use to 5 billion gallons a year.

Since fuel ethanol was first used in the early 1980s, there have been debates about whether corn-based ethanol provides energy benefits. Some critics argue that it has a negative energy balance (the energy in ethanol itself minus fossil energy used for corn farming and ethanol production).

Argonne is one of the research centres of the U.S. Department of Energy.