Biogas engines to convert methane into electricity

Brisbane Landfill is converting more green methane (landfill biogas) into renewable electricity following installation of two new 1.1MW landfill biogas engines at the landfill site in Rochedale. These new engines are expected to generate 18,250 MWh of renewable energy per annum, which is enough to electricity to power over 3300 Brisbane households on a 24/7 basis.

The renewable electricity generated by these new engines are also expected to offset a further 14,391 tonnes of greenhouse gas emissions from Queensland’s electricity grid each year. This is equivalent to the yearly emissions from 4580 cars.

Landfill biogas is a by-product of the slow decomposition of organic material in landfills. This natural process produces a biogas, which consists predominantly of methane (50%) and carbon dioxide (50%). It is estimated that one tonne of garden waste in landfill produces 1.4 tonnes of carbon emissions over the life of the landfill and one tonne of food waste will produce 1.9 tonnes of carbon emissions over the life of the landfill.

Brisbane City Council has a long-term commitment to reducing emissions from landfill. Every year, more than three quarters of the biogas produced at the Brisbane Landfill is captured and used to generate electricity or flared to destroy the methane component. Brisbane City Council also capture the biogas produced at five closed landfills across the city.

At the Brisbane Landfill, Brisbane City Council and LMS Energy work together to capture biogas as it is produced, ensuring that as little as possible escapes into the atmosphere. The biogas is captured by installing biogas wells into the waste and placing a vacuum on these wells to capture the biogas that is produced. By capturing this biogas, Brisbane City Council and LMS reduce over 400,000 tonnes of carbon dioxide equivalent from being emitted into the Earth’s atmosphere each year through the emissions abated at the landfill and the emissions offset from the Queensland electricity network.

Once captured, the biogas is used as a fuel to power a bioenergy power station, which converts the biogas into green, renewable electricity. This renewable electricity is then sent into the local electricity network, where it is consumed by local residents and businesses, offsetting fossil fuel usage.

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The two new 1.1MW landfill biogas engines will join the existing fleet of five engines installed at the Brisbane Landfill.

The existing five landfill gas engines generate approximately 45,500MWh of baseload renewable energy per year. This is enough to power 8300 homes every year and reduces grid electricity emissions by approximately 36,400 tonnes of carbon dioxide equivalent emissions.

The two new landfill gas engines, which were installed by LMS Energy, will increase the renewable electricity generation capacity at the Brisbane Landfill by 40%.

Jason Dockerill, Contract and Client Manager with LMS Energy, said it was exciting to be working with Brisbane City Council to expand the Rochedale Bioenergy Facility.

“This project will provide significant additional environmental benefits and further highlights Council’s commitment to reducing the city’s carbon footprint,” he said.

“This biogas renewable energy project is yet another example of Australia’s waste not only powering but supporting the transition to a circular economy. LMS is proud of the strong working relationship it has with Brisbane City Council and commends the Council on their commitment towards best practice waste management, and their emissions reduction efforts.”

Capturing and converting methane into electricity isn’t the only way Council’s waste facilities are reducing emissions. The Brisbane Landfill administration building, as well as the Willawong, Chandler, Nudgee and Ferny Grove resource recovery centres have rooftop solar panels which provide around 610MWh of renewable solar electricity annually.