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From the Editors of E/The Environmental Magazine Turning Trash into PowerWaste-to-energy plants: Is this alternative fuel worth the pollution?What do you think of those waste-to-energy plants used by cities to generate power? —Christine Ramadhin, Queens, NY
Waste-to-energy facilities, which generate power by burning trash, have been in widespread operation in the U.S. and Europe since the 1970s and are considered by environmental advocates to be a mixed blessing. On the one hand, they get rid of garbage without adding to already stressed landfills and with the added benefit of contributing electricity to the power grid. On the other hand, they do generate toxic pollution, usually as a result of burning vinyl and plastics. Waste-to-energy facilities evolved out of basic incinerator technology that simply burns trash and reduces it to ash and smoke. Waste-to-energy plants instead use the garbage to fire a huge boiler. When the garbage fuel is burned, it releases heat that turns water into steam. The high-pressure steam turns the blades of a turbine generator to produce electricity. In the U.S. and Europe, environmental laws regulate waste-to-energy plants, typically requiring them to use various anti-pollution devices to keep both harmful gases and particulate pollution (fine bits of dust, soot and other solid materials) out of the air. However, the particles captured are then mixed with the ash that is removed from the bottom of the waste-to-energy plant’s furnace when it is cleaned. Environmentalists contend that this toxic ash, which can include dangerous heavy metals, may actually present more of an environmental problem than the airborne emissions themselves, as it usually ends up in landfills where it can leak into and contaminate soil and groundwater. According to Greenpeace International, waste-to-energy facilities are also among the largest sources of dioxin emissions in industrialized countries. Dioxin is a by-product of burning polyvinyl chloride and other plastics, and has been linked to cancer and other health problems. Greenpeace advocates phasing out waste-to-energy facilities in favor of improving recycling rates that reduce the waste stream in the first place. Currently about 600 waste-to-energy facilities are in operation around the world. According to the National Solid Wastes Management Association, an industry trade group, the United States is home to 98 such plants operating in 29 states. These facilities manage about 13 percent of America’s total trash output. In Canada, where landfill space is more abundant, waste-to-energy has failed to catch on, with only a few such facilities across the country. Waste-to-energy has caught on more so in smaller technologically advanced countries such as Japan, Sweden, Denmark, France and Switzerland, where landfill space is at a premium. Recent improvements in the energy efficiency and environmental impact of waste-to-energy facilities mean that the technology promises to play a larger role globally in years to come, especially as crowded developing countries start to jump on the bandwagon. For more information: • National Solid Wastes Management Association: www.nswma.org. • Greenpeace Incineration Campaign: www.greenpeace.org/international/campaigns/toxics/incineration. Got an environmental question? Send it to: EarthTalk, c/o E/The Environmental Magazine, P.O. Box 5098, Westport, CT 06881; submit it at www.emagazine.com/earthtalk/thisweek: or e-mail [email protected]. Read past columns at: www.emagazine.com/earthtalk/archives.php. |
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