Several Studies Contradict Pimentel Ethanol Findings (7-19-05)

The National Corn Growers Association (NCGA) disputes a study conducted by Cornell University’s David Pimentel and University of California, Berkeley, professor Tad Patzek that states ethanol has a net energy balance loss of 29 percent. In fact, ethanol has a substantial net energy gain of at least 67 percent, according to one study.

Pimentel has been routinely discredited by a growing body of government and academic research, including studies by the Departments of Agriculture and Energy, the Colorado School of Mines, Michigan State University, Agri-Food Canada and others.

NCGA President Leon Corzine called the Pimentel study a last-ditch effort to derail the Congress’ positive momentum toward an 8-billion-gallon renewable fuels standard.

“This is the goal line stand by the opposition,” he said. “We have worked extremely hard to get the energy bill where it is today and show the nation the importance of the 8-billion-gallon renewable fuels standard. We have people that have been in opposition and they continue to be. It’s the fourth quarter and we’re pushing the RFS over the goal line. Their goal line stand is very predictable.”

“It’s abundantly clear that both corn ethanol and cellulose ethanol displace crude oil and save liquid fuels,” said Bruce Dale, professor of chemical engineering at Michigan State University. “Dr. Pimentel’s net energy argument is bogus. What counts is whether we can displace imported oil, and ethanol certainly does so.”

Corzine said Pimentel and Patzek are the only researchers since 1995 who have found ethanol to have a negative energy balance. In fact, the nine other energy balance studies conducted since 1995 all found net energy gains of at least 25 percent. NCGA called into question the credibility of Pimentel and Patzek.

”Maybe the problem is Pimentel is an entomologist instead of an engineer,” Corzine said, adding that Patzek was a longtime employee of Shell Oil Company and founder of the UC Oil Consortium, which has counted BP, Chevron USA, Mobil USA, Shell and Unocal among its members. Patzek also is a member of the Society of Petroleum Engineers, making his ethanol energy balance analysis hardly impartial, Corzine said.

“It’s interesting to note that Mr. Pimentel now has ties--direct ties--to the petroleum industry,” Corzine said. “We continue to offer the chance for debate and we continue to get no response from Mr. Pimentel. The facts are on our side and we will get the energy bill passed by the end of the month.”

Leading academics also discredited the work of Pimentel and Patzek. “In terms of finer details, Pimentel and Patzek use old data, improper data, and their methods of data analysis are wrong. For example, they don’t give proper energy credits to dried distillers grain, a coproduct of ethanol production” Dale said. “There is an internationally accepted standard method of doing such life cycle studies. Drs. Pimentel and Patzek don’t come close to meeting the standards. Their studies don’t meet the International Standards Organization test of transparency—they don’t clearly state where their data comes from nor do they clearly state their assumptions. They cite themselves rather than independent sources for important data all the time. And they don’t submit their work for verification in recognized, peer-reviewed life cycle journals.

“I invite Dr. Pimentel to submit and publish his work in the International Journal of Life Cycle Analysis journal as we have done with our study on ethanol net energy.”

In June 2004, the U.S. Department of Agriculture updated its 2002 analysis of the issue and determined that the net energy balance of ethanol production is 1.67 to 1. For every 100 BTUs of energy used to make ethanol, 167 BTUs of ethanol is produced. In 2002, USDA had concluded that the ratio was 1.35 to 1. The USDA findings have been confirmed by additional studies conducted by the University of Nebraska and Argonne National Laboratory.

These figures take into account the energy required to plant, grow and harvest corn—as well as the energy required to manufacture and to distribute ethanol.

The net energy balance of ethanol production continues to improve because ethanol production is becoming more efficient. For example, one bushel of corn now yields at least 2.8 gallons of ethanol—up from 2.5 gallons just a few years ago.

Dale said researchers ought to be focusing on energy quality, rather than continuing to debate over Btus lost or gained.

“Every single energy conversion system we have—whether it is coal to make electricity, crude oil to make gasoline, solar cells to make electricity—they all have negative energy overall if you take everything into account.. That’s the laws of thermodynamics,” Dale said. “But what we do is trade off a loss of energy quantity for increased energy quality. We can’t light our homes with coal, so we lose some energy in coal to make the remaining energy more useful as electricity. Likewise we convert corn, using natural gas and coal, to make a valuable liquid fuel, ethanol, which clearly reduces our need for imported oil.”