Major contract awarded to power NZ Battery investigation

Energy and Resources

A consortium of specialist firms has been awarded a major contract to advance the New Zealand Battery Project’s feasibility investigation into a pumped hydro storage scheme at Lake Onslow, the Minister of Energy and Resources Megan Woods has announced.

“This contract represents a major milestone as it begins the targeted engineering, environmental planning and geotechnical feasibility investigation for Lake Onslow,” says Megan Woods.

The consortium, Te Rōpū Matatau, will be led by engineering consultancy Mott MacDonald New Zealand, with engineering consultancy firm GHD, and environmental planning and design consultancy Boffa Miskell.

“The first part of this investigation will look at the design and environmental effects as well as determining the geotechnical fieldwork programme.

“The second part will refine the design, informed by fieldwork investigations of key geotechnical aspects, including the regional geology, rock properties, fault lines and the availability of rock and earth fill at location for potential dam construction. The environmental planning work will look at consenting options and what further work may be needed to assess the environmental effects.

“The fieldwork investigations are likely to include drilling shallow and deep boreholes to better understand the underlying geology, the best route for a tunnel and the best location for a potential underground powerhouse. “This work, along with the environmental and cultural investigations already underway, will give a better picture of the feasibility and costs of the Lake Onslow storage scheme.

“I want to thank mana whenua and the local community, particularly the landowners around Lake Onslow for their patience as we look to conduct investigations and acknowledge the challenging and unique situation they are in. While this project has the potential to benefit all of New Zealand, the project team will continue working with and supporting these groups,” Megan Woods said.

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Notes to editors

The NZ Battery Project is investigating solutions to the ‘dry year problem’ when hydro catchments are low and fossil fuels are burnt to generate electricity to cover the shortfall. A number of options are being investigated and will be compared to a pumped hydro storage scheme option at Central Otago’s Lake Onslow. The contract for this Lake Onslow feasibility study is worth approximately $11.5m.

What is pumped hydro storage?

Pumped hydro technology involves transferring water between two reservoirs at different heights. Water flows from one reservoir to the other through tunnels, passing through a power station. When electricity demand is low or when surplus power is available, electricity is used to pump water from the lower reservoir to fill the upper reservoir. When water stored in the upper reservoir is released, it flows down the tunnels to drive turbines that generate hydro-electricity. Water in the upper reservoir effectively acts as a ‘battery’, as it can be released to generate electricity when it’s needed during times of high demand or during dry years.