David Pimentel

David Pimentel, a retired Entomologist? has been critical of ethanol and other biofuels. His studies contend that corn ethanol, and biofuels in general, are "energy negative", meaning they take more energy to produce than is contained in the final product.

In a 2006 article in Science? he offersed an opinion that current corn ethanol technologies have similar greenhouse gas emissions to gasoline, but are much less petroleum-intensive than gasoline.

In 2000, Dr. Michael Wang?, of Argonne National Laboratory?, wrote that ethanol by-products are the most contentious issue in evaluating the energy balance of ethanol. He wrote that Pimentel assumes that corn ethanol entirely replaces gasoline and so the quantity of by-products is too large for the market to absorb, and they become waste. At lower quantities of production, Wang finds it appropriate to credit corn ethanol based on the input energy requirement of feed product distillers grains that the ethanol by-product? displaces. In 2004, a USDA report found that co-products accounting made the difference between energy ratios of 1.06 and 1.67. In 2006, MIT researcher Tiffany Groode? came to similar conclusions about the co-product issue.

External Links:

Northeast Biofuels Collaborative

PDF Energy Balance