Everyone knows food is fuel for the body. An experiment in California’s East Bay is showing it also could be fuel for homes—if digested properly.
Food waste from restaurants, fish markets and school cafeterias in Oakland have been making their way into the mouths of two anaerobic digesters to be converted into renewable energy by the East Bay Municipal Utility District. Wastewater treatment facilities have been using anaerobic digestion for years to treat solid waste and produce methane gas and fertilizer. But results from this pilot project found anaerobic digestion of food waste produced more than three times the methane—which can be used as biogas—than digesting municipal wastewater solids (sewage sludge, basically). The Environmental Protection Agency, which funded the program with a $50,000 grant, reported, “Anaerobically digesting 100 tons of food waste per day, five days a week, provides sufficient power for an estimated 800 to 1,400 homes for one year.”
Food waste accounts for 5.9 million tons, or 16 percent, of California’s municipal solid waste. According to the EPA, only a wee 2.5 percent of food waste is composted nationwide.