Crops, crop residues, and forest residues, as well as energy crops planted on idle or marginal crop land, could be converted to various form of energy, such as ethanol, biodiesel, and biopower. Ethanol from grains now account for almost all of U.S. biofuel production. In 1999, about 1.5 billion gallons of ethanol were produced by 58 ethanol plants located in 19 States. This year production is projected to increase to 1.6 billion gallons. Total US production capacity is 1.87 billion gallons with another 175 million gallons under construction and over 600 million gallons are under planning.
Efforts are under way to convert cellulosic materials, such as grass and wood, to ethanol.
Four companies are planning to build cellulosic ethanol plants in the United States in the near future. According to Department of Energy projections, cellulosic ethanol production by 2010 may increase to about 300 million gallons. Currently, corn stover is a feedstock of choice due to its large concentrated supply and relatively low cost compared to other feedstocks. Because ethanol only accounts for 1.2 percent of the U.S. gasoline supply, its price does not affect the overall price of gasoline. Instead, the price of ethanol is affected by the price of gasoline, other oxygenates, and octane.