Glossary
Landfill gas
Landfill gas is a complex blend of different gases created by the action of microorganisms within a landfill as they decompose organic waste, including for example, food waste and paper. This gas is approximately forty to sixty percent methane, with the remainder being mostly carbon dioxide. Methane is a potent greenhouse gas, and when it's not captured, landfill gas contributes to global warming.
Landfills are the third-largest source of methane emissions in the United States, and so management of these emissions has significant environmental implications. When a landfill is first constructed, the organic waste begins to be broken down by the microorganisms in an anaerobic process (without oxygen), leading to the generation of landfill gas. If left unmanaged, this gas escapes into the atmosphere, increasing greenhouse gas emissions.
However, properly managed landfill gas presents a valuable opportunity within the green and renewable energy industry. Modern landfills now actively collect the produced landfill gas, using a systematic network of wells and a vacuum system to transport it to a central point. Here, it’s processed and treated to remove impurities and then can be used as an extremely effective source of renewable energy.
The process converts methane, which if left alone would contribute significantly to atmospheric warming, into carbon dioxide, which still contributes to warming, but less significantly. In addition to this conversion, the energy potential of the methane is also harnessed for productive use. Landfill gas can generate electricity, be used directly for hot water or space heating, and provide fuel for vehicles. Therefore, management of landfill gas significantly reduces greenhouse gas emissions while also generating sustainable renewable energy.
Where the carbon accounting industry is concerned, landfill gas represents a critical aspect. The collection and utilization of landfill gas have the potential to earn carbon credits under many regulatory regimes, which can be an additional financial motivation for organizations to invest in landfill gas capture systems.