Two new studies put ethanol's energy balance at about 1 to 4, says Cole Gustafson, NDSU Extension biofuels economist.
For years scientists have been arguing whether the ratio exceeds 1 to 1.
Ethanol's energy balance is the amount of energy produced divided by fossil energy needed to produce it.
USDA and the University of Illinois did the studies. Both relied on survey data from operating ethanol plants.
Farmers get most of the credit for the improvement. The amount of energy used to grow corn has declined by almost 30%.
Source: NDSU Extension Communications