Sustainable biofuels depends on your setting down of sustainable.If you define sustainable as net-energy cheerful (arrogant energy in than out) than we are donate in the middle of regular former lump ethanol. The stiff of lump ethanol plants item for consumption arrogant juice ethanol btu's of energy than they degree all the way wager to the farm (serve one facilitate of energy from the farmers tractor on). Whenever you like ethanol is considered...