Final Word on Ethanol's Efficiency as Vehicle Fuel


A study by the University of California at Berkeley says that use of ethanol as a transportation fuel offers a positive life cycle energy balance, while producing slightly fewer greenhouse gas emissions than petroleum fuel use. Dan Kammen and Alex Farrell of the Energy and Resources Group (ERG) at the UC Berkeley published their research in the journal Science. While earlier studies suggested that the energy to produce ethanol was greater than the actual energy content of ethanol, this overview work argues that those assertions were incorrect. The ERG research report also noted that most ethanol today is produced through corn and, as such, the subsequent greenhouse gas emissions thought to cause global warming are only marginally cut. That will change, however, when such non sugar feedstock sources as switchgrass are put to use on a large scale, supplanting corn.The UC Berkeley study examined several earlier assumptions and then corrected for errors and outdated information as it relates to how much energy it takes to grow corn and then make ethanol. The study says that ethanol produced from corn creates 10-15 percent fewer greenhouse gas emissions than burning gasoline. Similarly, a study from the International Energy Agency in Paris agrees, saying that while grain-based ethanol requires substantial amounts of fossil fuel inputs, that fuel additive is still responsible for creating 20 percent fewer greenhouse gas emissions than conventional fuels.

For a list of errors and omissions corrected for in previous life cycle inventory studies reviewed click here.

The following studies were reviewed by the Energy and Resources Group:

Fossil Energy Use in the Manufacture of Corn Ethanol
by Dr. Michael S. Graboski, Colorado School of Mines, Prepared for the National Corn Growers Association (2002).

The Energy Balance of Corn Ethanol: An Update
Hosein Shapouri, James A. Duffield, and Michael Wang, U.S. Department of Agriculture, Agricultural Economic Report No. 814 (2002).

The 2001 Net Energy Balance of Corn Ethanol
Shapouri, H., Duffield, J., Mcaloon, A.J. Proceedings Of The Conference On Agriculture As A Producer And Consumer Of Energy, Arlington, VA (2004).

The Greenhouse Gases, Regulated Emissions, and Energy Use in Transportation (GREET) Model, version 1.6 Michael Wang, Transportation Technology R&D; Center, Argonne National Laboratory.

Thermodynamics of the Corn-Ethanol Biofuel Cycle
Patzek, T.W., Critical Reviews in Plant Sciences 23(6), 519-567 (2004).

Ethanol as Fuel: Energy, Carbon Dioxide Balances, and Ecological Footprint
Marcelo E. Dias de Oliveira, Burton E. Vaughan, and Edward J. Rykiel, Jr. BioScience, 55(7), 593 (2005).

Ethanol Production Using Corn, Switchgrass, and Wood; Biodiesel Production Using Soybean and Sunflower David Pimentel and Tad W. Patzek, Natural Resource Research, 14(1), 65-76 (2005).

Finally a cohesive and circumspect study published in a reputable journal. We think it's time to get over the Ethanol benefits hangover and move on with the serious business of producing small (2 to 4 passenger) hybrid cars that can be fully recharged from exteral power as well as run with a flex-fuel powered ICE engine.

If the US is serious about scientific learning and technological development, lets take it up a notch. Let's offer low interest loans on these for every top eschelon graduate of an accredited engineering or business school, conditional upon them taking a prerequisite group of ecology and environmental managment courses. Lets make it cool to design green. What though do we offer to the farmers?