Cornell professor David Pimentel has just published another study critical of ethanol and other biofuels. Pimentel has published several studies over the last several years that have all come to the same conclusion that it takes a lot more energy to produce ethanol than the finished ethanol contains. And these studies always get a lot of press and are quoted by every ethanol critic as being the gospel but he has had a habit in the past of using old data and questionable substitutions for co-product values to arrive at his conclusions. In this study he concluded that basically no biofuels are worth the effort.
Their paper then looks at the efficiency and costs associated with converting a range of crops into energy and shows that in each case more energy is required for this process than they actually produce as fuel. The research finds a negative energy return of 46 percent for corn ethanol, 50 percent for switchgrass, 63 percent for soybean biodiesel and 58 percent for rapeseed. Even the most promising palm oil production results in a minus 8 percent net energy return. There are also a number of environmental problems linked to converting crops for biofuels, including water pollution from fertilizers and pesticides, global warming, soil erosion and air pollution.
So far all I have been able to find is the summary posted by the journal that the study was published in. Hopefully over the next few days I will be able to see the full study and find out the data he used to come up with his conclusions.
Source : ScienceDaily
4 comments:
So, what's his solution to the current energy crisis? Do we remain stuck to oil from countries that cannot be relied on? If indeed he claims more energy is required to produce renewable ethanol or cellulosic ethanol, why don't we try to produce them using oil, and then try the same process with renewable energy? I can't wait to see where this approach can take us. I think there's a bright future for cellulosic ethanol and other forms of renewable energy. Let's give it a try and not allow some academic theories distract us from the drive to wean ourselves from foreign sources of energy.
Pimentel is opposed to commercial agriculture so his opposition to biofuels is no real surprise. I don't think he is any real fan of fossil fuels either so his solution would most likely be a smaller global population and a lifestyle similar to preindustrial times.
Pimentals opinion is no better than anyone else. Every study is slanted to paint biofuels as a poor choice. He uses outdated data, and worse case scenarios. Of course he has an agenda to promote and that is all he has. He is not even an expert on agriculture of ethanol.
He should stick to bugs as every etomologist should.
I still haven't found a copy of the full study. I did look back at a study he did in 2003 and then he found that it took 29% more energy to produce ethanol than what ethanol contains. So he is the only person that I know of that thinks that ethanol is not becoming more efficient over time. Personally I think in the case of Pimentel and Patzek any time they do a study it shouldn't be accepted for publication unless they also evaluate gasoline using the same methodology.
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