Ethanol—Energy Waster or Booster?

The debate over whether or not producing ethanol from corn as a fuel wastes more energy than it produces continues over at the Wall Street Journal. WSJ numbersguy, Carl Bialik, cites an analysis done by Michael Wang, a vehicle fuel-system analyst at Argonne National Laboratories in which Wang calculates that "it takes 0.74 BTU of fossil fuel to create 1 BTU of ethanol fuel, compared with a ratio of 1.23 BTUs to 1 BTU for gasoline -- that's 66% more than ethanol." More details of Wang's analysis are available here.

If Wang is correct, that's good news. But even so, ethanol "energy independence" from imported oil will remain a mirage. And, I ask again, if ethanol is such a profitable idea, why do producers need federal subsidies?