







Surprised at the results, Patzek began an exhaustive analysis of his own -- one that painted an even bleaker picture of the ethanol industry's long- term sustainability.

"Taking grain apart, fermenting it, distilling it and extruding it uses a lot of fossil energy," he said. "We are grasping at the solution that is by far the least efficient."

Patzek's report also highlights the potential environmental hazards of ethanol production.

"When you dump nitrogen fertilizer on corn fields, it runs away as surface water, into the Mississippi River and Gulf of Mexico," he said.

The excess nitrogen introduced into the water causes out-of-control algae growth, creating an oxygen-poor "dead zone" where other marine plants and animals cannot survive. And while ethanol produces fewer carbon monoxide emissions than regular gasoline, some researchers have found that ethanol releases high levels of nitrogen oxide, one of the principal ingredients of smog, when burned.



"His figures (regarding energy consumed in fertilizer production) are accurate for older nitrogen fertilizer plants, but newer plants use only half the energy of those that were built 35 years ago," he said. He also cited the increasing popularity of no-till farming methods, which can reduce a corn farm's diesel usage by 75 percent. "With hydrogen fuel, people are willing to say, '25 years from now it will be good.' Why can't we also be forward-looking when it comes to ethanol?"



Shapouri's most recent analysis, which the USDA published in 2004, comes to the exact opposite conclusion of Patzek's: Ethanol, he said, has a positive energy balance, containing 67 percent more energy than is used to manufacture it. Optimistic that the process will become even more efficient in the future, he pointed out that scientists are experimenting with using alternative sources like solid waste, grass and wood to make ethanol. If successful on a large scale, these techniques could drastically reduce the amount of fossil fuel needed for ethanol production.

Other contributors to the debate argue that ethanol's net energy balance should not be the sole consideration when policymakers are evaluating its usefulness -- factors like the fuel's portability and lower carbon monoxide emissions need to be considered as well.

"So what if we have to spend 2 BTUs for each BTU of alcohol fuel produced?" reads an editorial in the Offgrid Online energy newsletter. "Since we are after a portable fuel, we might be willing to spend more energy to get it."

Cornell University ecology Professor David Pimentel, however, sides with Patzek, calling production of ethanol "subsidized food burning."

"The USDA isn't looking at factors like the energy it takes to maintain farm machinery and irrigate fields in their analysis," he said, adding that the agency's ethanol report contains overly optimistic assumptions about the efficiency of farming practices. "The bottom line is that we're using far more energy in making ethanol than we're getting out."

Patzek thinks lawmakers and environmental activists need to push ethanol aside and concentrate on more sustainable solutions like improving the efficiency of fuel cells and hybrid electric cars or harnessing solar energy for use in transport. If they don't, he predicts economics will eventually force the issue.

"If government funds become short, subsidies for fuels will be looked at very carefully," he said. "When they are, there's no way ethanol production can survive."