A recent UN report estimates that a third of all food produced worldwide, an estimated 1.3 billion metric tons, is wasted every year – not including the water, fertilizer, and other resources required to produce, store, transport, and, ultimately, dispose of it. In industrialized countries, the waste is often due to consumers buying too much food and subsequently throwing it away, as well as large-scale food waste from restaurants, hotels, supermarkets, and other similar businesses. In the developing world, inadequate storage facilities and inefficient farming techniques contribute to the problem.
In addition to the waste, food spoilage causes an enormous problem; it produces greenhouse gases (GHG) on a vast scale, enough to be the third largest source of GHG emissions after U.S. and China’s emissions from all sources. UN experts from the Food and Agriculture Organization estimate that wasted food produces the equivalent of 3.3 billion metric tons of carbon dioxide (CO2) emissions every year, and even more when you include the CO2 equivalent emissions associated with the various parts of the food production cycle.
Many strategies to stop food waste in the U.S. revolve around changing people’s behavior, which can be extremely difficult. However, there are ways to capitalize on the anticipated spoilage and turn it to an advantage. In Massachusetts, the Commonwealth recently awarded two grants totaling $400,000 to the Greater New Bedford Regional Refuse Management District and CommonWealth New Bedford Energy LLC to help develop a pilot program for the anaerobic digestion (AD) of food waste, fats, oils and grease, and sewage sludge.
Anaerobic digestion is the process of breaking down, or “digesting,” organic materials with micro-organisms and without oxygen. The byproducts generally include methane, CO2, and other greenhouse gases. AD has two significant benefits. The gases can be burned as renewable biogas to generate electricity – producing a cleaner and more renewable source of energy than fossil fuels. It also diverts tons of food waste from landfills.
Food and other organic wastes make up 25 percent of the Commonwealth’s waste stream, potentially providing fuel for new types of power plants powered by biogas produced through anaerobic digestion. By requiring some businesses to find alternatives for disposing of food waste starting in 2014, the Massachusetts Department of Environmental Protection’s (MassDEP) recently-announced commercial food waste disposal regulations are expected to expand the potential pool of fuel sources for anaerobic digesters.
The Massachusetts Clean Energy Center is helping with the process; its Commonwealth Organics-to-Energy program has begun accepting applications for projects that employ anaerobic digestion, or similar technologies that convert source-separated organic wastes into electricity and/or thermal energy. Electricity generation with biogas from anaerobic digestion is also supported through the Department of Energy Resources’ Renewable Portfolio Standard, and through net metering.
Anaerobic production of biogas is not a perfect solution to problems such as food waste, but it does provide a valuable stop gap measure that can both generate renewable energy and find a use for spoiled food beyond just throwing it away. If you want to know more, visit Anaerobic Digestion & Organics Diversion and Anaerobic Digestion: Questions & Answers.