Over the last four decades, we human beings have tripled our consumption of the earth’s natural resources, said a recent report from the United Nations Environment Programme. And according to the World Resources Institute “one half to three quarters of annual resource inputs to industrial economies is returned to the environment as wastes within just one year.”

Every year globally, tons of garbage or municipal solid waste is produced. Municipal solid waste consists of paper, cardboard, food, grass clippings, leaves, wood, leather, plastics, metals and petroleum-based synthetic materials. To sustainably manage or reduce this waste, it must be burnt in waste plants to produce a new energy.

Burning the waste in waste-to-energy plants does not only reduce volume of municipal solid waste, but can also harness its embedded energy and put it to good use. Most of these plants are mass burn facilities. Waste is stored in large bunkers, then transported to a moving grate in a furnace where it is burned at over 850˚C for at least two seconds to ensure complete combustion. The heat from the furnace heats water in a boiler, creating steam that turns a turbine to drive a generator that makes electricity. The electricity then enters the grid. 

Some plants combine electricity generation with a district heating system, using the excess steam to create heat used to heat homes. About a small percentage of what is left after burning is a non-hazardous bottom ash; some of it is used for cover at landfills to reduce leachate or is landfilled. In some parts of the world, this ash is often used in the construction industry or for road building.

Besides sustainably managing waste, waste-to-energy plants provide other benefits, such as gate fees (the fee per ton paid by the municipality to the facility for receiving the waste), the electricity and/or co-generated heat that is produced, the value of scrap metal collected, and potentially, carbon credits for renewable energy.