New Zealand / Environment

'A task in itself': Country's largest solar power station built in Kaitāia

16:32 pm on 27 November 2023

Aerial view of Lodestone Energy's Kaitāia solar farm, currently the biggest solar generator in the country. Photo: Supplied / Lodestone Energy

New Zealand's biggest solar power station to date has started producing electricity in the Far North.

With a connection capacity of 23MW, Lodestone Energy's solar farm, just outside Kaitāia, eclipses any other completed so far around Aotearoa.

The next biggest is a 5.2MW solar farm in Gisborne, which started operating just this month.

Lodestone's general manager of development Daniel Cunningham said commissioning started late last week with the first of six power inverters now supplying power to the national grid.

The remaining inverters would be hooked up gradually with the process due to be completed by late January.

Cunningham said the project was on budget and only a few weeks behind schedule.

"So it's pretty well on time, which we think is quite an achievement. It hasn't been an easy year to be constructing a solar farm with that massive rainfall early in the year. It was a task in itself to build New Zealand's first grid-scale solar farm."

The Kaitāia solar farm was the first in the country big enough to be required to "bid" into the power market.

That meant the company had to tell the electricity market operator how much power it was going to generate each half hour, allowing supply to be matched with demand.

New Zealand's biggest solar power station has been built on 80ha of farmland at Gill Road, near Kaitāia. Photo: RNZ / Peter de Graaf

The 60,000-panel solar farm had been built on 80 hectares of farmland on Gill Road, just north-west of Kaitāia.

The exact cost has not been disclosed but Cunningham said it was about $60 million.

Unlike most solar farms built so far in New Zealand, the panels were mounted on motorised trackers which followed the sun for maximum power generation.

The panels were raised on two metre high poles so farming could continue underneath.

Cunningham said sheep would be brought on site "any day now".

The company would then explore other ways of maximising agricultural production. That could include grazing cattle, growing crops, or horticulture.

A formal "switching on" and naming ceremony would be held once the solar farm was fully operational.

Most of the plant's power output, estimated to total 55GWh a year, had been contracted to the Warehouse Group and to electricity retailer Pulse Energy.

Cattle graze next to New Zealand's biggest solar power station, near Kaitāia. Photo: RNZ / Peter de Graaf

Meanwhile, Lodestone was planning another, even bigger solar farm just north of Dargaville, as well as projects in Edgecumbe, Waiotahe (near Ōpōtiki) and Whitianga.

Cunningham said the company had yet to make a final decision on the Dargaville project but he hoped construction would start by the end of 2024.

That would mean power could start flowing in late 2025.

New Zealand's current second-biggest solar power plant, the 5.2MW Te Ihi o te Rā, was switched on this month by Eastland Generation on 6ha of previously unused land at Gisborne Airport.

Prior to that the nation's biggest was a 2.1MW solar farm built at Kapuni, in Taranaki, in 2021.

Work is also underway on a 12ha solar farm at Pukenui, about 50 kilometres north of Kaitāia.

One of six inverters is craned into position at Lodestone Energy's Kaitāia solar farm. The inverters convert the panels' low-voltage DC output into high-voltage AC power suitable for transmission. Photo: Supplied / Lodestone Energy

That project, by Far North Solar Farms, was launched by then prime minister Jacinda Ardern in 2021 but appeared to have stalled for the past two years.

Earthworks have, however, started in recent weeks.

The peak generation capacity of Lodestone's Kaitāia farm is similar to that of Top Energy's 32MW geothermal power plant at Ngāwhā, near Kaikohe.

However, the geothermal plant runs at full capacity 24 hours a day and not just when the sun shines.

Earlier this month, commissioners for Environment Canterbury rejected a resource consent application for a solar power station in the Mackenzie Basin even bigger than Lodestone's in Kaitāia.

If it had gone ahead that solar farm would have covered about 110ha.

It was refused on ecological grounds.