There's no such thing as a free lunch and an electric motor turning an alternator is using more power than the alternator produces. *The difference is lost as heat.
As for ethanol, a bushel of corn can produce 2.7 gallons of ethanol, which is equal to ~2 gallons of gas. *Someone currently buying 10 gallons of gas per week would be using about 5 bushels of corn converted to ethanol. *A good yield of corn is 150 bushels per acre, so that 10 gallon per week gas consumption would take the corn produced by two acres. *A town of 10,000 people divided among 2,500 families each using 10 gallons of gas per week would need 5,000 acres. *That's about 8 square miles just to produce ethanol. I'm not checking my math, so I hope I haven't screwed this up.
Another way to look at it is that a bushel weighs 56 pounds, so that 10 gallon per week figure equals 15,000 pounds of corn per year. *That would feed a lot of people. *Since US farmland is pretty well maxed out, any substantial increase in corn (or any other fuel crop) production has to happen elsewhere. *So farmland in nations with serious malnutrition problems will be producing foodcrops to be converted into fuel for our cars. *And we think we have popularity issues now.