Despite having a much lower public profile than other renewable energy sources, recent figures from national grid operator Eirgrid revealed that landfills were responsible for 29 Megawatts (MW) . . . around 0.5% . . . of the state's total power output.

This might not sound like much but Bioverda's chief executive John Mullins believes that landfill-based power generation could play a big role in decreasing Ireland's reliance on fossil fuels. "With the technology, you are using methane to produce power rather than, for example, coal, which is cleaner from a carbon point of view."

Power generation using landfill gas takes advantage of the fact that as waste in a landfill decays, it emits methane, a highly flammable gas which, if it escapes into the atmosphere, has 25 times the global warming capacity of carbon dioxide.

By capturing the gas and burning it, landfill gas power generation systems ensure that only carbon dioxide and water are emitted into the atmosphere, while also generating renewable electricity.

According to Mullins, Bioverda's largest landfill gas installation, which is located at Kill in Co Kildare, can produce 11MW of energy, while reducing the amount of greenhouse gases emitted.

He said that it was relatively easy to install generators at landfills due to legal requirement that all landfills must have some mechanism of burning-off methane.

"Under the EPA licencing requirements, you have to have pipes to carry the methane to a burner. What we do is we put a compressor on the pipes so we can suck the gas out of the landfill and put into gas engines, which produce electricity."

Landfills continued to produce methane after they had closed, which meant that many sites could continue generating electricity for up to 15 years after they had finished accepting waste.

"Essentially all the piping is underground and hidden from the public under two metres of earth so a landfill could be used as a park, for example, and people wouldn't be able to see any of power infrastructure apart from the compound where the generators are."

In 2000, Sustainable Energy Ireland estimated that around 304MW of Ireland's power could be sourced from landfills by 2020 and Mullins said that every Irish landfill could have generation stations.

"But the one issue that works against this is that there are a lot of provincial landfills that would only produce 300 Kilowatts (KW) to 500KW of power and the cost of connecting them would make it unviable for them.

"But there is no reason for it not to work on larger landfills. It gives a positive aspect to the landfill as, rather than flare the gas and waste it, you can generate electricity from it."