The paper, “Wasted Food, Wasted Energy: The Embedded Energy in Food Waste in the United States”, by Amanda D. Cuellar and Michael E. Webber, both of the University of Texas at Austin, uses energy from agriculture, transportation (both from the field to the processor and from the processor to the store), processing, sales, storage, and preparation (home and restaurant) to calculate the amount of energy used in each step.
How Much Energy Is Used in Food Production?
About 8% of the total energy used in the U.S. goes to food production and consumption, or about 7790 trillion BTU. Unfortunately, about 27% of that energy is wasted, meaning a little over 2% of the total energy used in the U.S. each year is burned up for no reason.
The authors put together a nifty chart which shows how much energy is used at each step in the process. Agriculture, including chemicals, fuel, electricity, fisheries, and aquaculture (domestic and imported) uses 1240 trillion BTU. Transportation accounts for another 1650 trillion BTU.
The most interesting number to me is the residential energy consumption involved in preparing our food at home: 1570 trillion BTU, or 5233 BTU per person annually. (For ideas on reducing energy use in the home kitchen, check out the book Cooking Green.)
The paper continues through a series of calculations to determine which wasted food category (grains, vegetables, fruits, meat, dairy, etc.) has the highest amount of embedded energy use, which turn out to be dairy and vegetables.
But What Do We Do Next?
The challenge, of course, is how to reduce the waste of energy. Obviously, eating the vegetables and dairy products we buy before they go bad would help. But what about the food that spoils in the grocery store? During the transportation stage? I’m not sure where to start with those problems. Any ideas?
Image by Ingorrr, used with a Creative Commons license.