Southern Landfill Becomes Electricity Generator | infonews.co.nz New Zealand News

In a new energy project officially launched today, greenhouse gas from Wellington’s Southern Landfill is being used to generate electricity.

Wellington Mayor Kerry Prendergast and Todd Energy Managing Director Richard Tweedie presided at the official opening of the 1 MW generator plant which is expected to generate around 8 GWh of electricity per year – enough to power 1000 households – for the next 20 years. The Minister of Energy, Hon David Parker, and Chris Auchinvole, National's Associate Spokesman, Energy, were also on hand.

The generator is driven by a large internal combustion engine designed specifically to run on gas produced in the landfill.

"This landfill has been in use for over 30 years and is now producing a significant amount of landfill gas every year - including methane," said Mr Tweedie. "Methane is a significant greenhouse pollutant and harnessing it to produce electricity makes good sense from both an economic and environmental viewpoint."

Mayor Prendergast added that the City Council had been working with Todd Energy subsidiary Nova Gas for quite a few years extracting and flaring-off the gas generated by this landfill.

"There have been various proposals and attempts to make use of this greenhouse gas over the past 10 years or so. Technical or pricing issues have been challenging.

"So I'd like to congratulate Todd Energy and its team for seeing the opportunity presented by the methane to generate electricity for our region and for shouldering the business risk to turn this opportunity into a reality."

Mr Tweedie advised that designing a viable, long-term solution to the problem of managing greenhouse gas produced at the landfill had involved the generation expertise of Todd Energy subsidiary Bay of Plenty Energy teamed up with the specialist gas knowledge of Nova Gas, the company's Wellington-based gas retailer and pipeline operator.

"The generation plant has been selected for its high efficiency and its capacity to maximise the electricity produced from the available gas," said Mr Tweedie. "Depending on future waste volumes received and the content of the waste there may be sufficient gas to enable the installation of additional generation units in years to come."

Mr Tweedie believed the idea of utilising greenhouse gases to produce electricity would appeal to the more environmentally aware consumers who were concerned about the impact their household was having on the natural environment. Nova Gas has recently begun retailing gas and electricity to households in the Wellington region.

Mr Tweedie said the team was already looking at options to increase the electricity output through refinements to the gas recovery systems and was also investigating ways to increase the overall efficiency of the plant by utilising the waste heat produced as part of the generation process.

Mr Tweedie complimented the positive input of the Wellington City Council and the supporting role it had played in helping to make the project a reality.

"As the owner of the Southern Landfill, the Wellington City Council has proven itself to be an excellent partner in this project and we look forward to working with the team on further projects where the commercial, environmental and regional objectives are so well aligned."

The generation plant is located right next to the new and expanded Recycling Centre, on the right as you head up the hill just before the weighbridge. The new Recycling Centre gives landfill visitors far more room to move when manoeuvering vehicles, says Cr Celia Wade-Brown, the Council's Environment Portfolio Leader and the location of the plant means it is highly visible to landfill visitors. "It's a far bigger and better site – and is better able to deal with the increasing amount of recycling being done by Wellingtonians."

Cr Wade-Brown said it is the organic matter among that rubbish that had been filling up the landfill for more than 30 years – mainly the likes of garden clippings and food waste – that is now producing a large amount of landfill gas every year - including methane. "It's far better to make practical use of this gas than just flare it."