Landfill Gas To Electricity

Overview

Large municipal or industrial landfills produce considerable quantities of gas that can be tapped to generate electricity. The ACUA’s landfill, like many others, contains significant portions of organic materials that produce a variety of gases as they decompose.  Microorganisms thrive in the oxygen-free environment, resulting in the decomposition of the organic materials and the production of gases such as carbon dioxide and methane. Carbon dioxide is likely to leach out of the landfill because it is soluble in water. Methane, on the other hand, which is less soluble in water and lighter than air, is likely to migrate out of the landfill.

This methane, which comprises roughly 60 percent of the landfill gas, happens to be a powerful source of electricity. Methane is also a highly potent agent of global warming and causes about 21 times more damage to the ozone than CO2. Landfill gas (LFG) to energy facilities capture the harmful methane gas, which would otherwise be released into the atmosphere or burned off in a flaring process, and then combust it for energy, providing a clean, renewable source of electricity; making LFG the only form of renewable that directly reduces pollution to the atmosphere.  Most LFG projects are available to generate power 90 percent of the time, 24 hours a day, 7 days a week. Using landfill gas also reduces the need to use more polluting forms of energy, such as coal and oil. 

The methane is collected by drilling "wells" into the landfills, and collecting the gases through pipes. The landfill gas that is collected is cleaned, cooled and dewatered.  After it is processed, it can be transformed into electricity or combined with natural gas to fuel certain automobiles. Landfill gas may also be used in fuel cell technologies, which use chemical reactions to create electricity, and are much more efficient than combustion turbines.

As of December 2008, approximately 480 LFG projects were operational in the United States. These 480 projects generate approximately 12 billion kilowatt-hours of electricity per year, enough to power a million homes, and deliver 255 million cubic feet per day of LFG to direct-use applications. EPA estimates that approximately 520 additional landfills present attractive opportunities for project development.

The ACUA’s LFG facility became operational in March of 2005, and the methane captured from the landfill provides enough energy to power the entire Environmental Park, and the remaining gas going to the grid where it can be used to power area homes and businesses. For more information about the ACUA’s landfill gas project click here.   

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