Corn Power Put to the Test

There is only one catch: Turning corn into ethanol takes energy. For every gallon that an ethanol manufacturing plant produces, it uses the equivalent of almost two-fifths of a gallon of fuel (usually natural gas), and that does not count the fuel needed to make fertilizer for the corn, run the farm machinery or truck the ethanol to market.
But if ethanol is to realize its potential, its proponents recognize that they will have to develop new ways to make it without using so much natural gas

nytimes