Argument: Cellulosic ethanol packs many times the energy of corn ethanol
David Biello. "Grass Makes Better Ethanol than Corn Does." Scientific American. January 8, 2008: "yields from a grass that only needs to be planted once would deliver an average of 13.1 megajoules of energy as ethanol for every megajoule of petroleum consumed—in the form of nitrogen fertilizers or diesel for tractors—growing them....switchgrass ethanol delivers 540 percent of the energy used to produce it, compared with just roughly 25 percent more energy returned by corn-based ethanol according to the most optimistic studies."