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