Food scraps = Power: San Francisco utility generates power from food wast
November 9, 2009
From USA Today: OAKLAND — While many see restaurant leftovers as trash, a San Francisco-area utility sees them as a source of energy. The East Bay Municipal Utility District, which provides water and wastewater treatment in the eastern San Francisco Bay Area, is turning food scraps from 2,300 Bay Area restaurants and grocery stores into electricity to help it power its wastewater facility.
The San Francisco-area utility district powers its wastewater plant, which serves about 650,000 Bay Area homes, by capturing methane gas by processing many kinds of waste, starting with wastewater. To take up excess capacity, the utility started collecting other waste in 2001, including that from wineries, dairies and chicken processors, says David Williams, director of wastewater for the utility.
Food scraps from restaurants and hotels were added in 2004. The plant now processes 100 to 200 tons of food scraps a week. The goal is to do 100 to 200 tons a day – enough to power the equivalent of 1,300 to 2,600 homes – and rapid expansion is now expected. By the end of next year, the district expects to create so much power from non-traditional waste that it’ll be able to sell excess power to Pacific Gas & Electric, a local electricity supplier, Williams says. Read more