Using current data to examine the energy balance of corn ethanol, when looking at both corn production and the ethanol conversion process, it is clear that ethanol production is at the favorable end of the measurement, says Alan Tiemann of the Nebraska Corn Board. Tiemann is a corn grower from Seward.
“Several recent studies have made this abundantly clear,” he says, “including one at the University of Nebraska.”
Ken Cassman, director of the Nebraska Center for Energy Sciences Research, says earlier studies that examined ethanol’s energy balance sheet were based on backward looking data.
“These studies looked at older technologies with regard to energy use in corn production, the biorefinery and coproduct use,” Cassman says. “Recent research conducted at the University of Nebraska clearly shows that estimates for the energy balance of corn-based ethanol are much more favorable – in fact two to three times more favorable than previous estimates.”
Cassman, who is also a Heuermann Professor of Agronomy at the university, says it is important to understand that ethanol has a substantial net positive direct energy balance – that 1.5-1.6 more units of energy are derived from ethanol than are used to produce it. “Using dated information simply doesn’t work in a world where the technology and efficiency of corn and ethanol production are rapidly improving over the years,” he says.
“Moreover, if the goal is to reduce dependence on imported oil, we estimate that 13 gal. of ethanol are produced for every gallon of petroleum used in the production life cycle for corn ethanol,” Cassman says.
Tiemann adds that the research using current data also shows that the greenhouse gas emission reductions are also more favorable than previous estimates when compared directly to corn and ethanol production.
Compared to just five years ago, Tiemann says, ethanol plants produce 15% more ethanol from a bushel of corn and use about 20% less energy in the process. At the same time, corn growers are more efficient, producing more corn per acre and using less energy to do so.
“We must also remember all the useful coproducts that come from ethanol production,” Tiemann says. “The most important is distillers grains, a nutritious animal feed. Distillers grains have value, and they can’t be ignored when calculating the energy balance of corn-based ethanol production.”
In addition to a positive energy balance, Tiemann says it is also important to keep in mind some of the benefits of ethanol production. “We’re talking about energy security and energy diversity, and keeping more of our energy dollars in this country,” he says. “Those kinds of positives are good for the U.S. as a whole, and specifically for rural America, where renewable ethanol is produced.”The Nebraska Corn Board is a self-help program, funded and managed by Nebraska corn farmers. Producers invest in the program at a rate of 1/4 of a cent per bushel of corn sold. Nebraska corn checkoff funds are invested in programs of market development, research and education.