Why is Wasted Food a Problem?
According to The U.S. Department of Agriculture, 30-40% of the food in America is wasted. In 2017 alone, almost 41 million tons of food waste was generated and only 6.3% of that waste was diverted from landfills and incinerators for composting. Wasted food also represents a significant misallocation of resources. When we waste food, we are also wasting agricultural resources. For instance, wasted food ends up consuming nearly a quarter of our water supply in the form of uneaten food which equates to about $172 billion in wasted water. Add to this the time, energy, fossil fuels, chemicals, and other resources needed to grow and produce our food and the true scale of the impact of food waste becomes clearer.
This misallocation of resources is evident when we consider that although almost 40% of our food is wasted, 1 in 8 Americans are food insecureopens PDF file . Instead of throwing our food away, we could be using it to feed hungry people or animals. The U.S. Department of Agriculture estimates that 11.8% of American households had difficulty providing enough food for all their members due to a lack of resources in 2017. The EPA’s Food Recovery Hierarchy provides a prioritized list of actions to reduce food waste and address our misallocation of resources. The top levels of this hierarchy show the best ways to prevent and divert wasted food because they create the most benefits for the community, economy, and environment. As you can see in the pyramid, the best use for wasted food is feeding hungry people.
However, wasted food is not only an issue of wasting resources and feeding hungry people. It is also an issue that affects our climate. Food waste is contributing to about 8 percent of total greenhouse gas emissions globallyopens PDF file . All of the wasted food that ends up sitting in a landfill generates a powerful greenhouse gas, methane, which is 84 times more potent than carbon dioxide. So, by reducing wasted food, you can also begin to tackle the issue of climate change.
What is Anaerobic Digestion?
Anaerobic Digestion is a process by which organic matter, such as animal waste or wasted food, is broken down by bacteria in the absence of oxygen. This is usually done in a container called a digester. The process creates fertilizer that can be used for farming and biogas composed mostly of methane. The biogas can be combusted to generate electricity and heat, or it can be processed into renewable natural gas and transportation fuels. According to the Environmental Protection Agency (EPA), some types of organic matter break down more easily than others. The materials that break down easier generally produce more biogas. Figure 1 below from the Environmental Protection Agency illustrates the elements of a biogas recovery system.
Anaerobic Digestion offers a valuable and innovative way to divert waste from the landfill. An interesting example of someone who is taking advantage of this technology is Barstow’s Dairy and Bakery at Longview Farm in Hadley, Massachusetts. Their cows produce about a hundred pounds of manure per cow per day and they treat it through an anaerobic digester to generate electricity.
The Massachusetts Farm Energy Program (MFEP), a joint project of the Center for EcoTechnology and the Massachusetts Department of Agricultural Resources, offers a range of services to the farming community to reduce energy use and produce renewable energy that focuses on bringing projects from concept to completion. If you are a farm in Massachusetts working on an energy project and are interested in working with the MFEP, you can fill out their request form for more information.
Also, check out our recent appearance in the PBS NewsHour episode, How these Massachusetts farmers are turning manure and food waste into power, to learn more about anaerobic digesters in Massachusetts.