Study: U.S. waste could power 13.8 million homes
While U.S. recycling rates are trending upward and the amount of waste generated per capita is decreasing , an enormous amount of municipal solid waste (MSW) continues to enter landfills, remaining underutilized for energy generation and greenhouse gas reductions.
A new report authored by Columbia University researchers examines recycling rates and waste generation by state between the years 2008 and 2011, and finds that if all MSW landfilled in 2011 was diverted to waste-to-energy (WTE) plants, it would supply enough electricity to power 13.8 million homes. If the steam turbine exhaust of the WTE plants were to be used for district heating, as is done in Denmark and some other northern European countries, the waste steam could provide district heating for 9.8 million homes.
Although that scenario isn’t necessarily achievable, as it isn’t economical to covert MSW in all places to energy, potential to increase energy drawn from U.S. waste is great, the study finds.
For plastic alone—which make up 11 percent of the total waste stream—even though recycling rates increased by 21 percent between 2008 and 2011, and waste-to-energy plants took in 3.9 million tons or 9.9 percent, over 80 percent was still mixed in MSW disposed in landfills. Illustrating how meaningful the conversion of MSW to energy is, the report points out that every ton of MSW combusted in modern WTE plants replaces nearly half of a ton of coal. Therefore, diversion of MSW from landfills to new WTE plants could reduce coal mining in the U.S. by about 100 million tons per year, or 10 percent of U.S. 2012 coal production.
Furthermore, this scenario could replace all coal imported by states such as New York, California, Idaho, New Jersey and Maine, and drastically reduce annual landfilling in the U.S., which is estimated to require about 6,100 acres of land each year, or the equivalent of nearly 4,600 U.S. football fields.
The report also determines quantities of waste generated in the U.S. by state and how it is disposed of, highlighting that Connecticut, Maine, Massachusetts, Minnesota and New Hampshire, are closest to attaining sustainable waste management, by combining a high rate of recycling with a high WTE capacity to reduce landfilling.