Harnessing Landfills for Energy

Where can you find sources of renewable energy? Almost everywhere you look, according to a growing assortment of innovative projects seeking to replace fossil fuels with cheaper, cleaner forms of energy.

Forget about mundane energy sources like wind, solar power or corn, which can be made into ethanol fuel. The expanding crop of future fuel sources could include everything from bacteria to eggshells to garbage dumps.

Just this week, the U.S. Environmental Protection Agency (EPA) presented awards to several projects that work to capture methane gas emissions from the nation's landfills. By using those emissions to generate clean energy, the EPA says, these Landfill Methane Outreach Program (LMOP) partners also help reduce the amount of greenhouse gases entering the atmosphere.

Methane is generated when organic matter -- food scraps, grass clippings, dog droppings, etc. -- ferments in low-oxygen conditions such as those found inside landfills. Methane is also a powerful greenhouse gas; over a 20-year time span, it's estimated to be 72 times as damaging as carbon dioxide in terms of its impact on climate change. However, if captured before it enters the atmosphere, methane gas can be burned to drive gas turbines or steam boilers for generating electricity.

Among recent methane-to-energy landfill efforts deemed most innovative by the EPA are the Greentree High-Btu Landfill Gas Energy Project in Kersey, Pennsylvania; the Iris Glen Landfill Gas Energy Project in Johnson City, Tennessee; and the Southeastern Chester County Refuse Authority Landfill Gas Energy Project in Chester County, Pennsylvania.

The Greentree facility has become one of the largest methane-to-energy landfill projects in the U.S., according to the EPA. And the Johnson City project is used to supply steam, electricity and chilled water to a Veteran Administration hospital in the area, as well as to a local university and a civic center.

One company actively developing landfill methane-to-energy projects is the Ameresco Energy Services Company, which was named the EPA's Industry Partner of the Year during the 11th annual LMOP Conference and Project Expo held recently in Washington, D.C. Ameresco has a total of 22 landfill projects either in operation or in the design/construction phase.

Once completed, Ameresco says those projects will generate more than 110 megawatts of energy and remove the equivalent of 610,000 tons of carbon dioxide from the atmosphere every year. That's as effective as cutting coal consumption by nearly 25,000 rail cars full or reducing greenhouse gas emissions by planting more than 1.3 million acres of trees, according to the EPA.