Much of the overwhelming account of refuse being thrown into landfills every day is food waste, which not only overtaxes the landfills but also releases methane when it rots, a damaging greenhouse gas. Scientists and organizations all over the world are seeking ways to cope with food waste while at the same time searching for cleaner sources of power and energy. And in some instances they're coming up with creative solutions do both.
In January, British supermarket giant, Sainsbury, announced that it is planning to stop sending unsold food from all 28 of its stores in Scotland to landfills and divert it to a biomass refinery plant operated by the PDM Group. The company reprocesses food products used in the manufacture of bio-fuels to generate electricity. The liquid fat from the food waste is used in the production of biodiesel or as a renewable energy fuel.
Sainsbury expects to divert 42 tons (U.K.) of waste a week from landfills. The company expects that each ton of food waste diverted from the landfill will generate enough power for 500 homes and save three tons of CO2. The move will also result in approximately 336 waste-removal trucks being taken off the road as a single truck can be used to travel to all the Sainsbury stories in Scotland to collect the food waste and deposit it at the biomass plant.
Coincidentally (or not), Sainsbury's announcement comes on the heels of the opening of rival U.K grocer, Tesco's, new energy-efficient store in Manchester, boasting a carbon footprint 70 percent lower than a comparable store built two years ago. The eco-friendly Tesco store was built with skylights, automated energy-management systems, and new refrigeration units cooled with carbon dioxide rather than traditional gases, cutting energy bills by 48 percent and serves as a blueprint for future stores. Tesco plans to cut emissions by half in all new and existing stores and distribution centers by 2020.
Other companies leading the way in turning food waste into energy include Bellisio Foods, the Minnesota-based maker of Michelina's and other frozen meal brands. A family-owned business, Bellisio built its first waste digester in 2004 and is now building its second 5.25 million-gallon digester at its production facility in rural Ohio. The combined capacity of the two digesters will generate enough methane gas to power two boilers in the plant and is expected to completely eliminate shipping of the company's organic or food waste to landfills.
Meanwhile, in Boylston, Massachusetts, Owl Power Company, a developer and manufacturer of clean energy cogeneration systems, announced VegawattTM, a new cogeneration system for restaurants and food service facilities. Vegawatt uses waste vegetable oil as fuel to provide onsite electricity and hot water, saving users money along with providing a clean, renewable source of energy. The system has been installed at Finz Seafood & Grill in Dedham, Massachusetts since early December 2008, and its owner, George Carey, is quite pleased with the results.
"My largest line-item expense is runaway utility costs, " he says, "and the Vegawatt system enables me to significantly reduce my energy costs, generate clean energy onsite, and very importantly, reduce the heavy energy footprint of my restaurant." Most food service businesses pay to dispose of their used cooking oil, and some have begun to receive compensation for the oil, typically from $0.10 to $0.25 per gallon. Vegawatt owners should receive $2.55 per gallon.
During these rocky economic and climate-challenged times, finding innovative, green uses for food waste seems to make perfect sense.