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Tuesday, March 26, 2013

Revisiting the Energy Return and Merits of Soybean Biodiesel

In the current issue of Scientific American, there is an article with nice multiple graphics to educate people about today’s higher cost of producing energy as measured by the EROI. Energy return on investment (EROI) is the value used to represent the energy obtained per unit of energy spent to obtain it. The article titled, “The True Cost of Fossil Fuels,” is written by Mason Inman, who is writing a biography of geologist M. King Hubbert, the “father of peak oil.”
Inman explains that even though much of the easy-to-extract oil is already gone, the average EROI of conventional oil, at 16, is still far higher than that of other liquid fuels. As we go after oil from more difficult places, however, that number continues to fall. He tells us that 5 to 9 is the minimum EROI required for industrial societies to function economically.
The following graphic (using Inman’s EROI values) puts some of today’s liquid fuel sources into perspective:
[Have a good look at the numbers for the tar sands and heavy oil from California.]
As shown, corn ethanol is on the bottom of the heap for the EROI of the included liquid fuels, at 1.4. Irrigated corn produced in Nebraska would be even lower. And corn ethanol’s not even close to fitting into the 5 to 9 required economic range, which is why it would not survive without the infrastructure subsidies and mandates that it has been afforded. This is why I rail against it here so often, assuming that my readers are familiar with this low EROI fact. It is not good to do so much damage to our environmental and exhaust our agricultural resources to produce a product which offers us nearly nothing in return.
More at this link:

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