Artist's impression of the Dargaville solar farm, Lodestone One, which would be the biggest solar power plant in New Zealand. Photo / supplied
Two huge solar power stations planned at Dargaville and Kaitaia will be a game-changer for power generation in New Zealand, the company behind the venture says.
Last month the Advocate revealed Lodestone Energy had applied for consent to build a solar power station on the outskirts of Kaitaia with 20ha of panels spread over 100ha of farmland.
It would feed an estimated 62GWh (gigawatt-hours) of power directly into Top Energy's Kaitaia substation, making it New Zealand's biggest solar power station.
Now, however, the company has revealed it plans an even bigger ''solar farm'' near Dargaville, with an output of 120GWh, as well as three others across the upper North Island.
The whole project will cost about $300 million with work on Lodestone Two, at Kaitaia, due to start later this year. Power should start flowing in late 2022.
If it gets a green light the Dargaville solar farm, Lodestone One, is expected to start supplying power by summer 2023-24.
It will be built just northwest of Dargaville with more than 125,000 panels totalling 30ha on 170ha of farmland.
The power station will be built on farm blocks on either side of Kaihu River with Waihue Rd forming its eastern boundary.
Like the Kaitaia power plant, the panels will be raised on posts 2m off the ground and spaced 8m apart to allow farming to continue underneath.
The panels will be mounted on 40m-long motorised tracking bases which will tilt to follow the sun.
The farm will provide daytime electricity to about 5000 people living along the Northern Wairoa River with surplus power flowing to Whangārei.
The other solar farms will be built near Whakatāne, Edgecumbe and Whitianga.
Combined the five plants would have more than half a million solar panels over 500ha of land, producing enough renewable energy to power 55,000 homes or the equivalent of more than 150,000 electric vehicles.
The project is privately funded with backers including Takapuna tech entrepreneur Guy Haddleton and Warehouse founder Sir Stephen Tindall through his investment company K1W1.
Lodestone Energy managing director Gary Holden, who is also a key shareholder, said it was the most ambitious solar venture in New Zealand to date.
''These farms are a game changer for the electricity market and will increase New Zealand's current solar generation eightfold ... Solar costs have fallen sharply in recent years and we are now at the point where grid-scale solar power, if well located, is the most economic form of new electricity generation.''
Holden said the project would also reduce the country's reliance on fossil fuels.
While the farms were designed to meet morning and late-afternoon peaks in electricity demand, rapid improvements in battery technology meant in the near future the farms should be able to store power generated during the day for distribution in the evening peak.
Holden said solar plants could be constructed quickly and at a lower cost than wind or geothermal power plants.
They were also environmentally friendly and used no water, made little noise and released zero emissions, he said.
The Kaitaia solar farm will be built on adjoining farm blocks off Gill Rd, about 3km northwest of the town.
To put the Lodestone plan in perspective, the Dargaville plant alone will produce about 30 times more power than New Zealand's current biggest solar power station in Marlborough.
Lodestone Energy is a new company but its managers have previously worked on renewable power projects in New Zealand, Australia and Canada.
More local generation will almost certainly bring lower power prices for consumers, a Lodestone manager says.
Director of development Daniel Cunningham said extra generation in Northland — from Lodestone's solar farms and Top Energy's geothermal plant at Ngāwhā — would ''definitely'' reduce local wholesale energy prices.
It would, however, be up to power retailers to pass those lower prices on to consumers.
Lodestone was looking at its options for getting into the retail business in Kaitaia and Dargaville so it could sell its power directly to end-users.
More generation in Northland would also make the region's power supply more resilient and less prone to outages than in the past, when much of its electricity had to come long distances and pass through Auckland.
As the company added storage batteries to its solar farms that would have a meaningful impact on the power grid's resilience not just in Northland but New Zealand-wide, he said.