We ferment corn for the same reason u eat it. It is quick and cheap to grow, we have a ton of it, and the sugars in it are easily broken down.
I wouldn’t say that we have a ton of it. Not at the scale we need to replace oil with ethanol. It takes 450 pounds of corn to produce the ethanol to fill one SUV tank. That’s enough corn to feed one person for a year. I’m sure you know that.
Everything other than corn, sugar, or the equilivants (wheat, sugar beets, etc) is years and years away from being ready to cut your gas bill.
You can buy a Prius and modify it to run 40 miles a day on grid electricity for ~30k out of pocket It does not make much financial sense (not as much as buying a used econobox like Toyota Corolla) but you can cut your gas bill today.
Those batteries on Prius’ are a problem. Think about the battery on your laptop. After a certain period of time, no amount of charging will do it. Same for the cars, from what I hear. Those batteries aren’t environmentally friendly – and probably not cheap either.
Prius NiMH batteries cost ~$700/kWh and last for around 10,000 charge/discharge cycles (depends on the mode of operation). They can be recycled.
