As landfills which hold municipal solid waste are closed the emissions from decay of the material in the landfill becomes a pollutant. That pollutant can either contribute to smog and the increase in greenhouse gases, or it can be used as an energy source. A free, environmentally friendly fuel, potentially harmful if released, is not being used everywhere? What are we thinking? So, the equipment needed to capture and process the landfill gas is not free and maintenance is not free, but as energy costs increase, the feasibility of harnessing landfill gas (mostly methane) is not going to be reduced. Yet, according to the US EPA (United States Environmental Protection Agency), less than half of the feasible sites have even implemented this technology. That means that we in the United States are letting power sufficient to supply over 808,000 homes waft gently into the atmosphere every day totally unused. That's the equivalent of 997 MW of electrical generation capacity. This map from the US EPA shows sites where this technology has been found to be feasible as well as currently running projects. [ad name="Adsense Small Horz Banner"] And, electricity generation is not the only use for landfill gas. The gas has also been fed into the municipal natural gas supply infrastructure or used to fuel vehicles equipped to run on natural gas.
But, perhaps, the most significant impetus to implementing technology to harness landfill gas is the pollution problem.
Methane released into the atmosphere is a major cause of ground-level ozone or smog. This is an immediate health concern especially to people living in highly populated or industrialized areas. That means, that authorities must implement technology to control the release of methane (usually by installing a flare)
whether or not they plan to use it for energy. It is only a matter of increasing the capital investment in technology to harness this energy source, and one that will provide a positive return on the public investment in energy production as well as population health (from reduced pollution). In all cases it will not prove feasible (such as very small landfills), but for the rest, it is rare to find such a win-win technology option available to us.