Drilling is about to begin for one of the key options of the NZ Battery Project geotechnical feasibility investigations.
Minister of Energy and Resources Megan Woods said the project has the potential to be the largest hydro project in New Zealand.
“The geotechnical investigations starting at Lake Onslow tomorrow, and those being proposed for the coming months, will provide valuable insight into the regional geology and its suitability in supporting pumped hydro infrastructure, that, if constructed, has the potential to support a fully renewable electricity system and help reduce greenhouse gas emissions from electricity,” says Minister Woods.
“The purpose of this geotechnical work is to get a good sense of what’s going on underground. That includes understanding things like rock strength, geological properties and features such as faults, landslides and shear zones, and the interactions between groundwater and surface water.”
The first hole will be drilled to approximately 100 metres. Core samples will be taken and tested, and monitoring equipment will be installed to monitor things like groundwater flow over the long term.
“This work will help determine the best tunnel route and location for an underground powerhouse, and ultimately, give a better picture of the scheme’s technical feasibility and costs. These technical investigations will inform the broader Lake Onslow feasibility study that also considers the environmental, cultural, and social implications.”
“A pumped hydro scheme at Lake Onslow is one of the options being explored by the NZ Battery Project, which has been set up to explore possible solutions to the dry year shortage problem in a 100% renewable electricity system. A dry year energy storage solution is key to removing our reliance on fossil fuels to generate electricity and will greatly help us reach our climate change targets.
“The work at the first site is expected to be completed in early May. If other resource consents and permissions are granted, there will be more work at other sites around the lake and the Teviot Valley area that is expected to be completed throughout the rest of this year,” the Minister said.
At most sites, a mobile drilling rig will drill boreholes around to 50 or 100 metres deep and extract core samples for analysis. Test pits will be excavated to sample material near the surface and non-intrusive geophysical surveys will also be undertaken.
Geotechnical work will take place on both private and public land such as road reserves. Any proposed work on private land will first be discussed with the landowners, Ms Woods said.
“While all sites will be remediated, we’re also doing everything we can in the planning stage to ensure the impact on the environment from this work is low. For example, each potential site is examined by an independent ecologist, archaeologist and cultural values assessor and following their advice, we can avoid sensitive environments and make sure appropriate measures are in place to further avoid or minimise the impact on these values.”
She said sites had also been selected to lessen any disruption to the local community.
“I appreciate this work creates uncertainty for those in the area, and I want to thank the local community and mana whenua for their willingness to work with us while we are in the information-gathering phase.”
The NZ Battery Project is also investigating the feasibility of other potential solutions to the dry year, including smaller pumped hydro schemes at other locations, other hydro-based options and alternative approaches such as bioenergy and hydrogen, she said.
For more information, visit www.mbie.govt.nz/nzbattery.