Landfill Gas

Barr Environmental's generation of green electricity from landfill gas has passed the 6 megawatt mark.

The scheme is now generating enough renewable energy to meet the annual needs of over 1,300 homes.

Electricity is generated from landfill gas on-site at our Auchencarroch facility in Dunbartonshire, and at Garlaff in Ayrshire.  This power is then fed into the national grid for home-owners and businesses to use.

Landfill gas is a mixture of methane, carbon dioxide, nitrogen, hydrogen, hydrogen sulphide, and oxygen.  It is produced from the anaerobic decomposition of biodegradable waste within a landfill site when waste breaks down in the absence of oxygen.

If left unchecked, landfill gas can accumulate within a landfill site, which has the potential to cause an explosion or fire hazard within the landfill itself.  Uncontrolled release of landfill gas to the atmosphere can contribute to global warming and its odour can be a nuisance to local communities.  At our sites, in partnership with CLP Envirogas, Barr Environmental have installed state-of-the-art landfill gas extraction systems which draw gas from the landfill and safely use it to generate electricity.

The gas passes through an extensive network of pipes installed within the landfill, during which it is dried.  It is then mixed with a small amount of air and fed into a series of internal combustion engines within an on-site compound.  Each engine burns the gas in a similar way that a car engine would run on petrol or diesel; this in turn drives a generator mounted at the front of the engine.

Generation of electricity from landfill gas produces at least 20% less carbon dioxide emissions than generation using fossil fuels, making it a more sustainable option.  Any gas surplus to requirements undergoes complete combustion within a flare system.

Finally, the electricity passes through a series of transformers to make it suitable for feeding into the national grid, from where it is distributed to consumers.