A recent study by Argonne National Laboratory found that ethanol generates 35% more energy than it takes to produce, reinforcing the fact that production of the corn-based fuel yields a net energy gain.
The findings of the Argonne study support earlier research conducted by the U.S. Department of Agriculture, Michigan State University, the Colorado School of Mines, the Institute for Local Self-Reliance and other public and private entities that determined ethanol has a positive net energy balance. A USDA study released in 2004 found that ethanol may actually net as much as 67% more energy than it takes to produce.
The U.S. Department of Energy's Office (DOE) of Energy Efficiency and Renewable Energy says the Argonne study, conducted by Michael Wang, should help quell debate about the net energy balance of ethanol.
"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," DOE officials state in a summary of the study. "In terms of key energy and environmental benefits, cornstarch ethanol comes out clearly ahead of petroleum-based fuels"
In the last 10 years, only two studies — both conducted by Cornell University entomologist David Pimentel — have found the net energy balance of ethanol to be negative. Many economists have questioned the validity of Pimentel's findings, arguing that he uses outdated data in his methodology.
The DOE summary of the Argonne study suggests some researchers fail to accurately account for solar energy when determining ethanol's energy balance.
"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," DOE states. "since the solar energy is free, renewable and environmentally benign, we shouldn't care."
Ethanol also has a positive benefit in greenhouse gas (GHG) emissions reduction, according to the Argonne study. Wang found that, on a per gallon basis, corn ethanol reduces GHG emissions by 18 to 29%.
To read the DOE summary of the Argonne study, click HERE.