Another link:
http://www.coe.berkeley.edu/labnotes/0305/patzek_print.html
"All told, he believes that the cumulative energy consumed
in corn farming and ethanol production is six times
greater than what the end product provides your car
engine in terms of power."
As with biodiesel, fuel ethanol might be a worthwhile use
of an otherwise wasted crop (e.g. pest infested and
unsuited for consumption), but I suspect the prof has a
point about the net energy budget.
I am not an Ethanol nut but I don't see these figures as being correct.
The heat required to distill mash into alcohol is about 170 degrees farenheit. You could use waste heat from other industrial processes to do it without using any more energy but even if you buy the energy to heat the mash we are not talking about high pressure and temps like in the refining of oil.
A farmer filling his tractor with diesel does not equal the energy costs of drilling and building multimillion dollar oil platforms.
Transportation is an advantage with oil through pipelines but the transportation of grain isn't much different than how we transport coal through railroads and barges and coal is considered a cheap energy for big power producers.
I would like to see how much energy is needed to make a gallon of gas vrs a gallon of ethanol to see how they stack up.
Personally I don't think ethanol will take off not because of energy but because corn will be too high a price thanks to demand for food and other uses.