Energy from Landfill Gas and Methane
Landfill gas, released as solid waste decomposes, can be used to generate electricity in a very cost-effective manner. This gas is a mixture of methane, carbon dioxide, and other organic compounds.
How is landfill gas captured and turned into energy?
Landfill gas, produced when anaerobic bacteria break down organic waste, is extracted using a series of wells or a vacuum system. Gas is then collected in a central location for processing. The gas may be used to generate electricity onsite, or it may be upgraded to pipeline-quality gas. Combined with natural gas, it can fuel conventional combustion turbines or used to fuel small combustion or combined cycle turbines.
Some landfills are too small or otherwise unsuitable for large-scale production. A microturbine, a type of combustion turbine, may be used at these sites. Microturbines generate energy by burning fuel (landfill gas) to spin a turbine which activates a generator. Landfill gas may also be used in fuel cell technologies, which use chemical reactions to efficiently create electricity.
Isn’t methane gas a cause of global warming?
Yes. This is a major benefit of processing and using landfill gas to produce energy. The methane produced by landfills is a potent greenhouse gas and thus a major contributor to environmental problems. However, when methane gas is burned, it converts to less harmful substances such as CO2 and water. Therefore, although landfill gas is neither entirely renewable nor completely clean as a fuel source, it has many benefits in comparison to fossil fuel sources of electricity generation.