On Ethanol's Energy Balance

There's been some talk in the media lately about the Plug-In Hybrids' 500 miles per gallon (imported) gasoline fuel efficiency; based on these cars' 100 mpg capacity and the fact that they could theoretically run on 80% biofuel and 20% (imported) gas.

But more coverage was recently given to David Pimentel and Tad Patzek and their report that stated

"it takes at least 29% more energy to convert maize and other biomass feed stocks into ethanol than the amount of fuel produced by the process."

Now, of course, the study has been solidly refuted, and these refutations have also been widely covered in the media, though mostly in the mid-west.

So - one biased study claims a -29% energy balance, another equally biased study claims a +167% energy balance. They call this science? With as much as $1/gallon in tax incentives for ethanol producers, it's hard to know who to believe.