July 17, 2005 – Vol.10 No.17
OIL VS ETHANOL AND BIODIESEL.
David Pimentel, professor of ecology and agriculture at Cornell University and Tad W. Patzek, professor of civil and environmental engineering at the University of California-Berkeley, have published a study that analyzes the energy potential of ethanol and biodiesel vs that of oil.
Their findings? Neither biofuel is worth the trouble. The fuels require more energy input, typically from fossil fuels, than they will give as output.
As would be expected, ethanol, biodiesel and renewable fuels advocates cried foul. The Pimental/Patzek study is flawed, they say.
For the record, the press release from Cornell says this in regard to the findings of the study which is published in Natural Resources Research (Vol. 14:1, 65-76): (This editor has not read the complete study.)
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 require 27 percent more fossil energy than the fuel produced, and
-- sunflower plants require 118 percent more fossil energy than the fuel produced.
Also note that the Cornell press release says this: ( More on this later.)
"In assessing inputs, the researchers 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 rebuttal to the Pimental/Patzek study, the National Biodiesel Board (NBB) noted that:
-- A 1998 life cycle study of biodiesel made from soybeans from the U.S. Department of Energy and the Department of Agriculture showed a positive energy balance of 320 percent (vs Pimental's negative 27 percent). Soybeans, unprocessed, are high in energy content.
-- Pimental/Patzek don’t provide detailed descriptions of their findings nor their sources of data. (Their report is published within 11 pages; the 1998 DOE/USDA study is 286 pages of charts and text.)
--- At least eight other peer-reviewed studies in the past 12 years gave biodiesel a positive energy balance. The Pimental/Patzek study was not submitted for peer review.
-- The Pimental/Patzek study uses data on soybean production from 1990, not 2002 data which is available.
-- Human labor, in terms of caloric input, then converted to fossil energy, was included in the new study. Why?
The National Ethanol Vehicle Coalition (NEVC) and the National Corn Growers Association (NCGA) echo these concerns and add that since 1995 nine studies have shown net energy gains of at least 25 percent in the production of ethanol. A U.S.D.A study from 2004 showed an energy balance of 1.67 to 1 in favor of ethanol.
Further questions, too, should be asked of the Pimental study:
-- Why aren’t costs associated with environmental pollution or degradation included in the analysis? (As above.) Both ethanol and biodiesel are cleaner burning fuels than gasoline and diesel. Environmental pollution and degradation also lead to human health problems and their associated costs. All these costs need to be included.
-- Pimental and Patzek assume that all ethanol requires fossil fuel in its production, but the process by Iogen of Canada uses the thermal energy from waste bio-products. It uses no fossil fuels. Pimental suggests that wood should be burned for heat (which pollutes the air) but why not be burned for the production of biodiesel and ethanol?
-- The analysis also does not include the true cost of oil for comparative purposes. The researchers talk about direct subsidies that artificially reduce the cost of biofuels, but what about the indirect costs associated with our over-reliance on imported oil? What about the Persian Gulf War of 1991 and the war in Iraq?
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