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You may be surprised to learn that landfills are the source of an increasingly valuable commodity – energy. All landfills generate a by-product known as landfill gas, which is an excellent source of renewable energy. Landfill gas (LFG, not to be confused with LPG) can be used either directly by industry or to generate electricity for public consumption. In fact, when landfill gas is handled effectively instead of being released into the environment, this previously ignored resource has a lot to offer.
Landfill gas contains approximately 50 percent methane, which makes it an excellent source of energy. On the down side, methane has a global warming potential of 21 relative to CO2. In other words, one ton of methane produces the same greenhouse gas (GHG) effect as 21 tons of carbon dioxide (CO2). Capturing and converting LFG into energy prevents it from escaping into the atmosphere in addition to energy production.
In addition to contributing to Green House Gas emissions when released into the atmosphere, LFG has many other negative effects. These include disagreeable odors, health consequences from toxic and carcinogenic trace substances, and an increased risk of explosion from buildup at the landfill sites or in nearby buildings and other structures. The volatile organic compounds in LFG also contribute to smog and place stress on vegetation around the landfill. Fortunately, these effects can be prevented by capturing and using this valuable commodity.
 There are two ways to manage LFG once it has been captured. It can be either flared (combusted under controlled conditions) or used as an energy source. When LFG is flared, the methane is converted into CO2. This reduces GHG emissions, eliminates odor problems and destroys contaminants. When LFG is used for energy, it conserves non-renewable sources of energy, such as fossil fuels. Either way, capturing and using LFG has a positive effect on climate change.
In 1999, 280 kiloton’s of methane were collected in Canada and either flared or used. These practices reduced GHG emissions by about 6 million tons of CO2 equivalent (eCO2), which has the same effect as taking 1.5 million cars off the road. What’s more, this quantity of LFG contains the same amount of energy as 3 million barrels of oil – enough to heat 160,000 homes.
Two common uses for LFG are electricity generation – produced by running engines or steam turbines – and combustion as an alternative fuel. LFG can also be used directly by industry and to heat large buildings and greenhouses. Either method displaces the CO2 that would normally be released if fossil fuels had been burned. Companies and municipalities alike are realizing the great potential for energy within their reach with LFG.
Landfill gas is a harmful Green House Gas which can damage the atmosphere. Collecting and combusting it, however, prevents a number of adverse effects, such as gas migration, foul odors and the potential for explosion. It also reduces the factors contributing to climate change and offsets the use of non-renewable sources of fuel.
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