The weekly email from the U.S. Department of Energy's (DOE) Office of Energy Efficiency and Renewable Energy ( EERE) arrived today and it contains one important number: 6.48 billion gallons. That's how much ethanol - almost all of it from corn - was made in the U.S. last year, a total that comes to an average of 423,000 barrels per day. Compared to 2006, this is an increase of 34 percent. Still, more corn will be needed to reach the Energy Independence and Security Act of 2007's new Renewable Fuel Standard for 2008: eight billion gallons. A problem? Not according to the Renewable Fuels Association, which says that current biorefinery capacity is 13.4 billion gallons per year. With 57 new refineries on the way, the eight billion gallons will be here before we know it.