Ethanol: energy balance

The claim that it takes more energy to make ethanol than it generates is widely recycled in both regional and national media and Professor Pimentel of Cornell is extensively quoted on this subject. We would like to offer an alternative perspective as follows:

• First, the USDA, in a very detailed study, evaluates nine different studies, including Professor Pimentel’s, and concludes there is a 34% energy gain for dry mill plants. (Source: Estimating the Net Energy Balance of Corn Ethanol)
   

• Second, we believe the corn ethanol plant in Sutherland Nebraska that we designed is one of the most energy efficient in the ethanol industry. On the same basis as the USDA study we can show a 44% energy gain.

• Third, as farming efficiencies, corn yields, ethanol plant efficiencies and energy technologies advance, this energy gain will continue to increase.
   

• Fourth, the DIRECTION of oil discovery and production leads to a DECLINING energy ratio. There is no way around this fact as oil reserves wane.
   

• Fifth, a recent article in the Post-Standard of Syracuse by Tim Knauss pointed out the following:

Pimentel's research is controversial and has been disputed by most other scientists who have studied corn ethanol production. After reviewing the research, the environmental group Natural Resources Defense Council in February 2006 dismissed Pimentel as "an outlier," saying his calculations diverge dramatically from other studies. "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", the council concluded.

Also, keep in mind that there is a small group of scientists that say global warming is a fallacy. At some point we need to look at what the majority of the experts are concluding, examine the information we have at hand and then form our own opinion.

• Sixth and last, the insightful paper, “Thinking Clearly about Biofuels”, points out very distinctly the deep flaws in the current debate and states:

“For over 25 years a small but vocal group of critics has argued that ethanol from corn has a negative net energy. This viewpoint has been widely disseminated and is a major perceived drawback to ethanol. Net energy analysis is simple and has great intuitive appeal. It is also dead wrong and dangerously misleading. If we are to make wise decisions as we embark on this brave new world of alternative fuels, we will need to carefully choose our metrics of comparison. Two complementary metrics suggest themselves. First, alternative fuels (e.g. ethanol) can be rated on their ability to displace petroleum; and second, ethanol could be rated on the total greenhouse gases produced per km driven.”

We highly recommend reading this paper for anyone that wants to fundamentally understand this net energy debate. Therefore it is the first reference listed below.

Summary

We believe both corn and cellulosic based ethanol are part of the path towards our long term goal of energy independence and our shorter term goal of a more secure energy future. Corn based ethanol is what is feasible now and we are optimizing our plants in every imaginable way, through practical application today.

The supporting attachments provide further thoughtful analysis, great attention to detail, authoritative sources and, most importantly, substance. They include third party research papers that can help us advance and resolve the debates rationally. As you read through this information you will see that these issues are extremely complex. Forming an opinion requires science, reason and intuition. Even if you just read the summary for these papers, you will gain some valuable insight which will feed your intuition.

Back to: Ethanol Facts & Fiction


Citations and References

1. Thinking Clearly About Biofuels
       Bruce E. Dale, Michigan State University
   
   
2. Corn Ethanol Energy Balance
   Steve Healey - KL Process Design Group, LLC
   
   
3. The 2001 Net Energy Balance of Corn-Ethanol
   Hosein Shapouri, USDA, James Duffield, USDA/OCE, Andrew McAloon,  USDA/ARS), Michael Wang, USDOE
   
   
4. Estimating the Net Energy Balance of Corn Ethanol
   An Economic Research Service Report by Hosein Shapouri, James A. Duffield, and Michael S. Graboski
   
   
5. Net Energy Balance for Bioethanol Production and Use
   From the US Department of Energy Energy Efficiency and Renewable Energy
   
   
6. A Rebuttal to “Ethanol Fuels: Energy, Economics and Environmental Impacts”
   Dr. Michael S. Graboski, Colorado School of Mines,
   Dr. John McClelland, National Corn Growers Association
   
   
7. Net Energy Balance of Ethanol
   Corn Input Comparison Chart
   Compiled by NRBP, 2005