Solid waste disposal sites are not often seen as opportunities for energy solutions. Landfill gas (LFG), a mixture of methane, carbon dioxide and trace constituents, is typically viewed as a liability because of explosions, odours, and increasingly, climate change concerns. However, LFG can be turned into an asset. Process of land-filling, LFG collection, electricity generation and Grid transmission is shown in following figure.
Use of LFG for power generation began in the United Kingdom (UK) in 1985 and government support for electricity from renewable sources has made this its dominant application. By the end of 1993 there were 49 power generation projects with a combined capacity of 80 MWe, generating 447 GWh of electricity in the year. In addition, the 12 direct use schemes using LFG as a fuel for kilns and boilers produced a further 9,200 GJ as heat.
LFG is currently the most important source of renewable energy in UK, providing nearly one-thirds of all renewable. UK LFG output doubled from 731.2 Mtoe in 2000 to 1464.7 Mtoe in 2006. Between 2006 and 2008, 7output increased by a more modest average rate of 3.7% per year.
However, the importance of LFG as a renewable energy source would decline in the future, as anaerobic digestion (AD) and incineration of waste will replace land-filling gradually.
Credits: Image and data linked to sources.