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Waste-to- Energy
 Waste-to-energy refers to any waste treatment that creates energy in the form of electricity or heat from a waste source that would have been disposed of in a landfill, otherwise known as municipal solid waste. Waste-to-energy is a renewable energy because its fuel source, garbage, is sustainable and is not depleted. According to the U.S. Environmental Protection Agency, waste-to-energy is a clean, reliable, renewable source of energy. Today, the U.S. burns 14 percent of its solid waste and there are 90 waste-to-energy plants in the United States.
Waste-to-energy plants work a lot like coal-fired power plants. The difference is the fuel. Waste-to-energy plants use garbage, not coal, to fire an industrial boiler. The same steps are used to make electricity in a waste-to-energy plant as in a coal-fired power plant:
- The fuel is burned where high temperature combustion completely destroys viruses, bacteria, rotting food and other organic compounds found in household garbage that could potentially impact human health.
- The heat generated turns water into steam; this can be used in a heating system or a factory.
- Typically the high-pressure steam turns the blades of a turbine generator to produce electricity.
- After any incombustible residue (ash) cools, magnets and other mechanical devices pull metals from the ash for recycling. This is an important step, since a waste-to-energy plant can recycle thousands of tons of metals from its ash.
- The really advanced technology in burning trash is the air quality (emission) control system. America's waste-to-energy facilities today meet some of the strictest environmental standards in the world and employ the most advanced emissions control equipment available including scrubbers to control acid gas, fabric filters to control particulate, selective non-catalytic reduction (SNCR) to control nitrogen oxides, and carbon injection to control mercury and organic emissions.
- Another challenge is the disposal of the ash after combustion. Ash can contain high concentrations of various metals and harmful chemicals that were in the original waste. The ash is tested for harmful substances and can then be reused for many applications. Most of the ash is used to build roads and make cement.
- Finally a utility company sends the electricity that was generated along power lines to homes, schools, and businesses.
Today, the average American throws away about 5 pounds of trash every day. Americans are producing more and more waste with each passing year and populated areas are running out of space for new landfills. Urban would greatly benefit from this type of energy because the source of fuel is readily available in large quantities, pollution will be reduced, there will be more landfill space, and ultimately the dilemma of waste management will be reduced.
You may not consider it but garbage is a wonderful mixture of energy-rich fuels. In 100 pounds of typical garbage, more than 80 pounds can be burned as fuel to generate electricity at a power plant. A ton of garbage generates about 525 kilowatt-hours (kWh) of electricity, enough energy to heat a typical office building for one day.
According to the Integrated Waste Services Association:
The energy produced by the nation's 90 waste-to-energy facilities is the electricity generating equivalent of 30 million barrels of crude oil.
For every ton of trash disposed in a waste-to-energy plant, there is one ton LESS of carbon dioxide emission released into the air due to avoiding land disposal and fossil fuel generation.
The energy produced by the nation's waste-to-energy plants is enough to meet the energy needs of 2.3 million American homes.
America's 90 waste-to-energy plants displace 7.8 million tons of coal that otherwise would be combusted for energy each year.
Many are concerned that burning garbage may harm the environment. Waste-to-energy plants can produce air pollution when the fuel is burned to produce steam or electricity. The burning of the garbage releases the chemicals and substances found in the waste. These chemicals can be hazardous to people and the environment if they are not properly controlled. Another concern is that waste-to-energy plants will impede recycling programs. If all the waste is burned then there will be little incentive to recycle used products. However because of the nature of most waste recycling and waste-to-energy can actually complement each other.
Waste-to-energy plants generate enough electricity to supply millions of households. However, providing electricity is not the only major advantage of waste-to-energy plants. In fact, it costs more to generate electricity at a waste-to-energy plant than it does at a coal, nuclear, or hydropower plant. The major advantage of burning waste is that it reduces the amount of garbage we bury in landfills.
Through the combustion of everyday trash in modern facilities, waste-to-energy plants provide feasible options to populations that would otherwise buy power from conventional power plants and dispose of their trash in landfills. Waste-to-energy power plants provide vital trash disposal services and generate clean, renewable energy.
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