Supporters of ethanol as a renewable energy source have claimed in the past that only 60% of the yielded energy is needed to produce ethanol, but the new study challenges that number.
"The researchers included such factors as the energy used in producing the crop, costs that were not used in other studies that supported ethanol production, said Pimentel" [one of the study's authors].Not wasting any time, the Canadian Renewable Fuels Association issued a press release refuting the results, stating:
"Over the past decade, only two studies, both of which were conducted by Cornell University entomologist David Pimentel, have found the net energy balance of ethanol to be negative. The overwhelming majority of scientists... have argued Pimentel's studies use outdated data and a flawed methodology."
One thing that had not occurred to me before was this: How much fossil fuel energy is expended to produce petroleum fuels? Is it a productive formula?