Support
- “Ethanol: Energy well spent”. Natural Resource Defense Council. February 2006 – “Corn Ethanol Studies We reviewed six studies published since 1990 that examine the energy return on investment for corn ethanol. These included studies authored by Marland and Turhollow (1991), Lorenz and Morris (1995), Graboski (2002), Shapouri et al. (2002), Pimentel and Patzek (2005), and Kim and Dale (2005). We calculated the energy return on investment for each study ourselves, using the value of the nonrenewable energy input to the manufacturing process specified by the author of each study and a common total energy output value of 23.6 megajoules per liter of ethanol Of the six studies that we compared, all but the Pimentel and Patzek study show renewable returns on nonrenewable energy investment for corn ethanol. Energy return on investment values for these five studies ranged from 1.29 to 1.65. The significantly lower energy return contained in the Pimentel and Patzek study can be attributed to a number of factors. First, Pimentel and Patzek reported significantly higher energy inputs to the agriculture, transport, industrial, and distribution components of the ethanol manufacturing process than any other research team over the last 15 years. Specifically, they reported approximately twice the electricity input in the industrial process compared to the other studies and nearly three times the energy input for feedstock transport. Pimentel and Patzek also reported two to three times more upstream energy inputs – energy used by the suppliers of commodities purchased by the farmer or ethanol manufacturer, such as nitrogen fertilizer – than the other studies. Additionally, they included upstream energy burdens not included in the other studies, such as personal energy consumption by laborers and the energy costs of manufacturing capital equipment. Excepting Pimentel and Patzek as an outlier, the energy return on investment values produced in the five other studies indicate that corn ethanol has a solid renewable energy return on its fossil energy investment – its use does indeed help reduce our fossil fuel consumption.”
US Department of Energy, Argonne National Laboratory
Has issued numerous studies supporting this view. Concludes in 2005 study that there is a net energy gain from Ethanol 3/28/2005 — This study concludes that Ethanol generates 35% more energy than it takes to produce.
The United States Department of Agriculture
- United States Department of Agriculture. “Estimating the Net Energy Balance of Corn Ethanol”. 1995 – “Studies conducted since the late 1970s have estimated the net energy value of corn ethanol. However, variations in data and assumptions used among the studies have resulted in a wide range of estimates. This study identifies the factors causing this wide variation and develops a more consistent estimate… We show that corn ethanol is energy efficient as indicated by an energy ratio of 1.24.”
- United States Department of Agriculture. “The Energy Balance of Corn Ethanol: An Update.” 2002 – “Corn ethanol is energy efficient… For every BTU dedicated to producing ethanol there is a 34% energy gain… Only about 17% of the energy used to produce ethanol comes from liquid fuels, such as gasoline and diesel fuel. For every 1 BTU of liquid fuel used to produce ethanol, there is a 6.34 BTU gain.” Full report (Acrobat file, 176 kb)”
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- The study found that not only is ethanol energy-efficient, it’s efficiency is steadily improving.
Corn growers
- National corn Growers Association has concluded that ethanol energy has a positive net energy balance, in a study that involved the USDA, Michigan State University, the Colorado School of Mines, the Institute for Local Self-Reliance and other public and private entities.[1]
The ethanol industry argues this point
University studies
- Michigan State University.
- Colorado School of Mines.
- UC Berkley – Dan Kammen, a physicist and energy expert at the University of California at Berkeley. “We found unequivocally that it does not take more energy than you get out of the amount of ethanol. So it’s a net good if you grow ethanol and use it.”[2]
Counter argument(s)
Comment & Debate