Ethanol provides 30-40% more energy than it takes to produce, according to a recent University of Nebraska study on the fuel’s net energy balance. The study, conducted by scientist Dan Walters, confirms earlier USDA research that shows ethanol has a positive net energy balance.

Studies are often cited that show ethanol production uses more energy than it produces, Walters says. But those studies are decades old and don’t take into consideration changes in agriculture and the ethanol production process, he adds.

The Nebraska study’s methodology assesses the amount of fossil fuel required to grow, transport and convert corn into ethanol. The amount of energy required to blend ethanol with gasoline and transport it to the pump is also considered.

Technological advances in ethanol conversion and plant efficiency are responsible in part for the positive net energy balance, Walters says, pointing to the fact that a bushel of corn now produces at least 2.7 gal. of ethanol, where as a bushel only produced 2.5 gal. in 1990. Ethanol co-products also factor into the equation because additional energy would be needed to make these products if they weren’t being made during the ethanol conversion process.

Crop production is also more efficient now than in the past, according to the study. Farm equipment, seed genetics, irrigation practices, crop management and nitrogen efficiency have all improved dramatically during the past 20 years. According to the research, the energy balance will continue to improve as farming and ethanol production practices become more efficient.