The Labour government proposed the $16 billion pumped hydro scheme at Lake Onslow — a high country lake above Roxburgh — would solve the country’s dry year electricity woes without using fossil fuels and support a path to 100% renewable electricity generation.
Geotechnical work and environmental investigations costing almost $5 million were undertaken at and around Lake Onslow, while desktop exercises-only were conducted to explore alternate geothermal, hydrogen and biomass options.
The Onslow proposal was the preferred option and the Cabinet proposed to advance it to the next stage — a detailed business case — alongside a geothermal approach.
However, National has committed to stopping work on the project, Southland MP Joseph Mooney told the Otago Daily Times.
Instead, National planned to fast-track investment in the new renewable energy sector.
"Our commitment is in the first 100 days we’re going stop work on the Lake Onslow scheme," he said.
"We want to cut red tape and drive investment and renewable generation, which will include solar, wind and geothermal in particular."
According to its Electrify NZ policy document, National opposed the Lake Onslow option because "it puts New Zealand’s climate change targets at risk by making electricity much more expensive, which threatens to slow electrification or stop it completely".
Specialist advice to the Electricity Authority earlier this year showed the dry year problem could be solved with further investment in renewable energy.
National said initial analysis of the project’s high costs — which had ballooned to four times initially projected, or $8000 per household — could "stifle electrification, increase annual emissions by half a million tonnes, reduce energy security, and have a chilling effect on other generation investments".
Mr Mooney said there was "an exciting energy future ahead".
The South was a region which had been a leader in electricity generation since the 19th century, he said.
"So we’ve got a long, proud history in this space, developed through to the dams we have and now we’ve got the commitments to really lean into renewable energy generation and transmission, which I think would be great for our region."
Ministry of Business, Innovation and Employment (MBIE) NZ Battery programme director John Doorbar said the shape of the Onslow project would be a question for the incoming government and MBIE was unable to comment.
