Could Lake Onslow’s pumped storage scheme be the game-changer New Zealand needs to meet its future electricity requirements?

​​Earl Bardsley is living proof that one man can make a difference – in this case to New Zealand’s electricity supply.

In 2002, Bardsley, Honorary Associate Professor at the University of Waikato, came up with the idea of using Lake Onslow in Central Otago as a reliable power storage facility to meet the country’s electricity needs during dry years.

The ‘dry year problem’ refers to the fact that, although blessed with an abundance of hydro-generating lakes and rivers, New Zealand runs into problems when lake levels are low. At these times, electricity has to be generated by expensive and polluting fossil fuels, which the Government is committed to phasing out by 2030.

“I was always looking for possibilities by which we might get alternative means of storage away from our scenic natural lakes. So that’s why I first started thinking about the Lake Onslow basin,” says Bardsley.

By year’s end, the Government will have decided whether or not to go ahead with the $4 billion project that may well turn Bardsley’s vision into reality. The decision to proceed will be based largely on the findings of a feasibility study known as the NZ Battery Project, the outcome of which will be announced in June 2022.

As Bardsley told Frank Film, at heart of the Lake Onslow scheme is the concept of pumped storage.

“What it amounts to is that we’re using Lake Onslow as a battery,” says Bardsley.

“When the prices are low, and there’s plenty of water around, we’ll pump water up into the lake. When there’s a dry year, we’ll have all this potential energy available which we can run back down to the Clutha River.

“By running it back down we can generate 1000 megawatts, and that means that we can do away with fossil fuel as a source of energy during dry years.”

The Minister of Energy and Resources, Hon Dr Megan Woods, is unequivocal about the significance of the project and what it could mean for the Government’s commitment to New Zealand’s energy being 100% renewable by 2030.

“Look, this will be a game changer. Not only will it enable us to decarbonise, and get to that 100% renewable electricity system, but, more broadly, across our energy system,” Minister Woods tells Frank Film.

As Bardsley further explains, “The example could be the dairy industry, and the production of milk powder, which uses a lot of energy.

If we use that energy from electricity as opposed to, for example, coal, then that’s better for the whole country.”

The magnitude of the project is illustrated in Bardsley's assertion that: “The culmination of the water storage volume, and the height about the Clutha River, means you could have the potential energy up there equal to all the hydro lakes of New Zealand put together.”

Both Bardsley and Minister Woods acknowledge that the wetlands adjacent to Lake Onslow would be a casualty of the project, with Minister Woods also noting that any cultural significance to the local rūnaka will need to be considered and addressed.

Local fisherman, Andrew Moore, indicates to the Frank Film crew the point on the hill where the new lake level would be. In spite of the fact that, should the project go ahead, the hut he’s been coming too for 30 years will need to be moved, he’s philosophical about it (while also not missing an opportunity to have a dig at city dwellers in the north):

“Well, we need it. We’ve got electric cars now! All those Auckanders and Wellingtonians [with] their electric cars plugged in at five o’clock.

“[You’ve] got to get the power from somewhere, don’t you,” says Moore.

No Elon Musk, Earl Bardsely may not fit the mould of today’s visionary hero. But, the sincerity, clarity and intellectual rigour of this old school academic is convincing.

Bardsley’s belief in the project is clear: “It would be good to see the whole thing go ahead. It will change the New Zealand energy scene for the next 50 years.”

Producer/Director: Gerard Smyth
Editor: Oliver Dawe
Story Producer: Rose O'Connor
Production Manager: Jo Ffitch
Sound Mix: Chris Sinclair
Production Asst: Romah Chorley

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