Landfill Power Generation

Landfill is a type of biomass used for power generation.

Landfill sites contain buried waste matter, which contains organic materials. As organic matter decomposes it produces a mixture of methane and carbon dioxide (two greenhouse gases) known as ‘landfill gas’. If these greenhouse gases are not collected they escape from the landfill into the atmosphere.

Landfill gas is a valuable resource that can be extracted and subsequently used as a clean, safe energy source to generate electricity or heat.

Landfill and Queensland

In Queensland, there are several landfill gas-to-energy sites in operation. Several sites have been constructed cooperatively between ENERGEX and the Gold Coast City Council.

At these sites, methane gas is captured and burnt in generators to produce grid connected electricity. Generators are located at Molendinar, Suntown and Stapylton.

Stapylton Landfill Gas Power Plant (Qld)

Gold Coast Council's EPA waste facility collects and burns waste gas, which is approximately 50% methane (CH4). The methane collected is used as a fuel to generate environmentally friendly renewable electricity.

Gas created in the cells of the landfill site by the biological breakdown of waste product is environmentally damaging, with unpleasant odours, noxious elements and global warming potential. However, by using the high energy content of the gas to fuel an engine and generate electricity, not only is electricity supplied to the National electricity grid with emissions far below a conventional power station, but the local landfill gas emission problems are greatly reduced.

The landfill gas extraction and power generation facility incorporates:

• gas pumping station to create a vacuum on the landfill network;
• flare station to burn off the gas unused in the generation of electricity;
• gas conditioning plant to reduce impurities to the landfill gas engine;
• gas compressor to provide gas at a suitable pressure to the gas engine;
• landfill gas engine and generator plant installed in a stainless steel canopy enclosure;
• transformer and switching station to increase voltage from the generator to high voltage, for connection to the local electricity supply grid for exporting the electricity generated.

To see this process in action, view our diagram of a Landfill Power Station below.



Landfill Power Station - To see the full-sized diagram, click on the picture.

Costs and Benefits of Landfill Power Generation

Benefits:

• Using biomass (in this case landfill) reduces methane gas emissions
• Using the landfill is an efficient use of waste products.

Costs:

• Much larger volumes of landfill are needed to produce the same amount of electricity as fossil fuels and recycling is reducing landfills available to produce electricity.
• A generation site on land fill needs to be relocated when the gas is fully exhausted.