Seattle’s primary electricity provider, Seattle City Light, has recently expanded its portfolio of energy sources to include an increasingly common source of electricity: trash. It may sound like a hare-brained scheme dreamed up by an environmental scientist, but it actually is an increasingly common source of electricity production. In most cases, the process simply involves capturing gaseous methane as its produced by decaying garbage in landfills. Once its collected, the methane is burned up creating a combustion reaction that powers a large generator. The generator itself powers a turbine which, while spinning, creates an electric charge that can then be delivered to customers or stored for later distribution.
Seattle City Light’s pilot waste-to-energy project, developed in 2010, was the result of an agreement between Seattle Public Utilities and Waste Management. Seattle Public Utilities is responsible for disposing of the city’s garbage via curbside trash pick-up. Waste Management also provides trash collection in the form of commercial and roll off dumpster services. They also own and operate the Columbia Ridge landfill which is where Seattle City Light now draws some 5.7 megawatts of methane-generated electricity.The utility company buys up all of the energy produced from the Columbia Ridge plant and is enough to power almost 6,000 homes. The landfill accepts waste from many different Seattle trash disposal companies, as well as others based in Oregon. This ensures a study supply of trash to keep the plant running at peak capacity.
This latest energy deal represents the company’s long-term goal of acquiring and developing more renewable sources of energy. Seattle City Light already generates 50% of its electricity from hydroelectric dams located along the region’s waterways. The remaining 50% of their output is sourced from a combination of nuclear, wind, solar, coal, and natural gas. But only 2.5% of their entire production is based on coal, which produces the most greenhouse gases and environmental contaminants out of every other energy source.
Hopefully, more cities will begin to put their trash to such good use. Waste-to-energy plants allow us to produce more electricity from common garbage that would otherwise be left to decay. The resulting power means less coal or other fossils fuels need to be burned in order to generate the same amount of electricity. So go ahead and throw your trash out today, because it just might end up powering our future!