According to environmentalists and a growing array of politicians, biofuels are going to dramatically reduce our dependence on foreign oil supplies, replace dirty fossil energy with “clean” renewable energy, and sharply reduce carbon emissions. The facts are rather different.In part because the ethanol industry is already well developed, the promoters of biofuels have focused their attention on ethanol to power the transportation sector. On Dec. 27, 2006, the Governors’ Ethanol Coalition, which consists of the governors of 37 states, sent a letter to Congress in which they asked Congress to require that 15% of motor fuels consumption on a btu basis consist of ethanol and...