Ethanol as an Alternative Source of Fuel.

Ethanol is now a major item of discussion as an alternate source of fuel. Many times it is discussed in the context of “energy independence.” How is this fuel source produced and what is are the costs and infrastructure involved? What are current federal and state subsidies of this production? If we wanted to have 30% of all our petroleum consumption come from ethanol in 2030, what policies and quantitative actions would need to be taken? What would be the environmental impact of such a policy? What is the energy input to grow the corn (or other product) compared to the energy taken out?