How Much Gasoline Could Cellulosic Ethanol Replace?
Studies suggest that cellulosic ethanol could yield at least four to six times the energy expended to produce it. The U.S. Department of Energy estimates that the United States could produce more than a billion tons of cellulosic material annually for ethanol production, from switchgrass grown on marginal agricultural lands to wood chips and other waste produced by the timber industry. In theory, that material could produce enough ethanol to substitute for about 30 percent of the country’s oil consumption. A University of Tennessee study released in November reached similar conclusions. As much as 100 million acres of land would have to be dedicated to energy crops in order to reach the goal of substituting renewable biofuels for 25 percent of the nation’s fuel consumption by 2025, the report estimated.
