The biofuels debate

An increasing number of articles have recently been critical of biofuels. Two that reached wide audiences are in National Geographic and Time. Both were highly critical of corn-based ethanol in the U. S., but viewed sugarcane-based ethanol in Brazil in a much more positive light. Corn is criticized because, as a major food and feed crop, diversion of the grain toward the production of ethanol has the effect of driving up food prices. Also, the energy balance (output to input ratio) is not that attractive (Nat’l Geog.: 1.3 to 1.0). By contrast, the energy balance for sugarcane, at least in Brazil, was cited as 8 to 1. This begs the question as to why sugarcane is not used for ethanol production in the U.S. If the energy balance for sugarcane were only half as good as in Brazil (4 to 1) this is still much better than for corn. If the energetics really do favor sugarcane, why can ethanol be profitably made from corn, but not from sugarcane? I put together some numbers, based on what I found on the Internet, to compare the sugarcane situation in Brazil and the U.S.