Energy Balance on Ethanol

Interesting article from Science Daily July 2005

Some excerpts include:
Cornell University and University of California-Berkeley study.
Pimentel, professor of ecology and agriculture at Cornelland Tad W. Patzek, professor of civil and environmental engineering at Berkeley,
Their report is published in Natural Resources Research (Vol. 14:1, 65-76).

"There is just no energy benefit to using plant biomass for liquid fuel," says David Pimentel, . "These strategies are not sustainable."

"The government spends more than $3 billion a year to subsidize ethanol production (little going to farmers) when it does not provide a net energy balance or gain, is not a renewable energy source or an economical fuel. Further, its production and use contribute to air, water and soil pollution and global warming,"

They considered such factors as the energy used in producing the crop (including production of pesticides and fertilizer, running farm machinery and irrigating, grinding and transporting the crop) and in fermenting/distilling the ethanol from the water mix. Although additional costs are incurred, such as federal and state subsidies that are passed on to consumers and the costs associated with environmental pollution or degradation, these figures were not included in the analysis.

In terms of energy output compared with energy input for ethanol production, the study found that:
* corn requires 29 percent more fossil energy than the fuel produced;
* switch grass requires 45 percent more fossil energy than the fuel produced; and
* wood biomass requires 57 percent more fossil energy than the fuel produced.

In terms of energy output compared with the energy input for biodiesel production, the study found that:
* soybean plants requires 27 percent more fossil energy than the fuel produced, and
* sunflower plants requires 118 percent more fossil energy than the fuel produced.

"Ethanol production in the United States does not benefit the nation's energy security, its agriculture, economy or the environment," says Pimentel. "Ethanol production requires large fossil energy input, and therefore, it is contributing to oil and natural gas imports and U.S. deficits."