Is ethanol really a green fuel?  A hundred years ago Henry Ford experimented with ethanol as a fuel for his internal combustion engine.  His conclusion was that despite burning cleaner it was only two-thirds as efficient as petroleum plus it absorbed water from the atmosphere.  The only benefit of using ethanol was as a "filler" in regular petroleum.

So why is ethanol considered green?  Primarily becuase it is derived from plant material, a renewable resource, and because Amercian maize farmers get subsidies for growing the stuff... and we all like helping farmers, right?

Well, ethanol may not be the perfect green fuel but if you hit the jump you can read a bunch of techie stuff about what American scientists are doing to develop the perfect, renewable biofuel. 

The bottom line is, "Hey we know ethanol isn't perfect, but we're working on that."

» The Economist