Energy from Waste (EFW)
EfW or waste-to-energy (WTE) is a process that takes municipal solid waste (MSW) –a.k.a. household trash -- and transfers it into combustion chambers where the waste is combusted and reduced to an ash that amounts to 10 percent of its original volume. The heat generated from the combustion process heats up water in steel tubes that form the walls of the chambers. The water is turned to steam and sent through a turbine generator that continuously generates electricity that is sent to the power grid.
Covanta’s facilities process 65 percent of America’s EfW volume and generate, in combination with our other renewable energy facilities, approximately eight percent of America’s non-hydro renewable electricity. Each year 20 million tons of trash is converted into 9 million megawatt-hours of clean, renewable energy and more than 9 billion pounds of steam sold to a variety of industries. Processing municipal solid waste at Energy-from-Waste facilities for energy generation (steam or electricity) helps reduce greenhouse gas (GHG) emissions otherwise created by landfills, fossil fuel-generated energy and the mining of virgin metals. As part of our process, we recover over 400,000 tons of metal annually for recycling that would have otherwise been lost in landfills. Covanta supports recycling and encourages communities to do so as much as possible. Communities that have an EfW facility typically enjoy higher recycling rates than the national average1.
Currently in the United States, approximately one-third of the ash that remains following the energy recovery process is approved for use as landfill cover, instead of soil, to reduce leachate (liquid that drains off decomposing waste at landfills). The rest is sent for co-landfilling with MSW or to a monofill where only ash is stored.
Over the past 25 years, the EfW industry has developed state-of-the-art technology that makes it one of the cleanest forms of energy generation. Covanta’s facilities meet or exceed the strictest federal standards set by the U.S. Environmental Protection Agency (EPA) and employ sophisticated technologies to achieve superior environmental performance. On average, EfW facilities average emissions are dramatically below the established limits —usually operating at 60-80 percent or more below the required limit. And Covanta is committed to doing even better.
Federal statutes and policies such as the American Recovery and Reinvestment Act of 2009, Department of Energy, Federal Power Act as well as over 25 states have classified EfW as a renewable technology.
Energy-from-Waste is a smart renewable energy choice:
• Clean power: EfW facilities supply clean, reliable, renewable energy with less emissions than landfill gas, coal, oil, and tie or are better than natural gas on certain parameters.
• Reliable: In contrast to the intermittent renewable power sources such as wind and solar, Covanta’s EfW facilities are online more than 99 percent of the time to provide reliable waste management and baseload power generation for communities.
• Less dependence on imported fuels: For every ton of waste processed at an EfW facility, we avoid the need to import one barrel of oil or mine one quarter ton of coal.
• Net Greenhouse Gas (GHG) Reduction: For every ton of waste processed at an EfW facility, almost one ton of GHG is avoided.
• A safe and effective solution for managing local trash generation: Less reliance on landfills and long distance shipping of trash across state lines preserves valuable land and resources with minimal disturbance to surrounding neighborhoods.
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1 From the research study entitled, “Recycling and Waste-to-Energy: Are They Compatible? 2009 Update” conducted by Governmental Advisory Associates. The study was partially sponsored by The Energy Recovery Council of which Covanta Energy is a member.