Alternative Energy

WOODLYN, PA - JUNE 1: Brian Warren of Aqua Wastewater Management, pumps out trap grease into his tank truck on June 1, 2007, in Woodlyn, Pennsylvania, a suburb of Philadelphia. The trap grease will be sold to Philadelphia Fry-o-Diesel, a local company producing biodiesel fuels. The trap grease will be dehydrated and turned into a clean-burning, renewable fuel used as a substitute for petroleum diesel fuel. Biodiesel is made from animal or vegetable fats and oils, and alcohol. The fuel properties of biodiesel are very similar to those of petroleum diesel and can be readily integrated into the existing petroleum diesel supply and transportation infrastructure. (Photo by Robert Nickelsberg/Getty Images)