Reply #2: There are processes which can make ethanol...

[punpirate]

... from wood. However, it's a more expensive process than ethanol from corn or other feedstocks with simple sugars. It requires a different complement of yeasts and a much more energy-intensive process of hydrolization of the wood, but it can be done.

But, frankly, Bush is just talking out of his ass with this one. Right now, the energy input is greater than the output, and it's going to stay that way for a while.