Ethanol can be used either as an alternative fuel or as an octane-boosting, pollution-reducing additive to gasoline. The U.S. ethanol industry produced more than 3.4 billion gallons in 2004, more than doubling the amount produced in 2000. As of January 2005, 81 ethanol plants in 20 states have the capacity to produce nearly 4.4 billion gallons annually. An additional 16 plants are under construction to add another 750 million gallons of capacity.
Source: U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy