Energy from municipal solid waste
Municipal solid waste (MSW), often called garbage, is used to produce energy at waste-to-energy plants and at landfills in the United States. MSW contains biomass (or biogenic) materials like paper, cardboard, food waste, grass clippings, leaves, wood, leather products, and other nonbiomass combustible materials like plastics and other synthetic materials made from petroleum.
In 1960, the average American threw away 2.7 pounds of trash per day. Today, the average American throws away about 4.4 pounds of trash every day. Of those 4.4 pounds, about 34% is recycled or composted, and about 13% is burned and converted to energy. The rest, about 53%, is discarded, mostly into landfills. About 85% of household trash is material that will burn, and about 61% of that is biogenic—material that is made from biomass (plant or animal products).
Waste-to-energy plants make steam and electricity
MSW is burned at special waste-to-energy plants that use the heat to make steam to generate electricity or to heat buildings. In 2013, there were about 80 waste-to-energy plants in the United States that generated electricity or produced steam. These plants burned about 30 million tons of MSW in 2013, and generated nearly 14 billion kilowatthours of electricity, about the same amount used by 1.3 million U.S. households in 2013. The biogenic material in MSW contributed about 52% of the energy from MSW that was burned in electricity-generating waste-to-energy facilities. Many large landfills also generate electricity by using the methane gas that is produced as biomass decomposes in the landfill.
Waste-to-energy is a waste management option
Producing electricity is only one reason to burn MSW. Burning waste also reduces the amount of material that would probably be buried in landfills. Burning MSW reduces the volume of waste by about 87%.