Christchurch high school gets free solar panels and 25 years of cheaper power

Saturday, 14 February 2026

COG Power managing director Chris Conner next to the roof at Hornby High, where a new solar array is being installed at no cost to the school.

Hornby High School has plugged into what its solar provider says will be the largest rooftop solar array on any school in the country – and it will not cost the school a cent upfront.

Christchurch-based company COG Power is installing a 203.4kW system on the Ōtautahi secondary school, under a 25-year power purchase agreement, or PPA.

The system uses 452 panels and two 110kW inverters, giving a peak output of about 203kW and an expected annual generation of roughly 280,000 kilowatt-hours – enough to power about 35 average homes for a year.

Managing director Chris Conner says the firm pays for, owns and maintains the array, and the school agrees to buy the electricity it produces at a discount to its normal retail power price.

“What we do is pretty simple,” Conner said. “COG Power will install our arrays on client sites at no cost to them, so there’s no [captital expenditure], and then we sell them discounted electricity over the course of a 25-year contract.”

Conner said he and his father-in-law, Dr Rod Carr, the former chairperson of the Climate Change Commission and a former University of Canterbury vice-chancellor, are among the shareholders behind the business, which was spun out of a central Christchurch property development company that built mixed-use projects on Lichfield St before the family turned its focus to energy.

Under the deal, whenever Hornby is using power and the sun is shining, it must take COG’s solar power first, then top up from its normal retailer. If, for example, the school uses 1000 units in a period and the panels generate 500, 500 units will come from the roof and 500 from the grid.

Dr Rod Carr, former Climate Change Commission chair, is among the shareholders behind COG Power.

Conner said the company is a straight commercial operator, not a charity.

“This is an entirely commercial solution, a for-profit company. It’s not a charity or anything. We don’t take any subsidies, we don’t take any grants. We set out to put a market solution into solving the energy transition, and this is one way of doing that.”

He said solar now generates electricity so cheaply that COG can fund large arrays, sell schools power at a lower rate than the grid, and still make a margin.

For schools, though, the “savings” do not show up as a smaller power bill.

Conner said when a school cuts its electricity spend, the Ministry of Education tends to reduce its utilities budget at the next review. That means less money in the board’s bank account, even if New Zealand Inc benefits overall.

To get around that, COG structures its school offer differently.

Instead of giving schools a visible 10% discount on each bill, it calculates what the discount would have been, parks that amount in a separate pot, then pays it back as a donation at the end of the year.

“Hornby will probably be more like 10 to 12 grand, but it depends how much they end up using,” Conner said.

“A $10,000 annual donation might be a rounding error to a large corporate, but for a school it can pay for the right teacher aide in the right classroom at the right time, and that can have an outsized impact,” he said at the launch.

Schools still receive two power bills – one from their normal retailer and one from COG – and any surplus solar in the holidays is simply sold back into the wholesale market.

COG Power managing director Chris Conner says the Hornby High project should deliver a $10,000 to $12,000 annual donation to the school.

COG already has six school arrays operating and two more signed, alongside community and council clients such as the former YMCA Bishopdale, now The Kind Foundation, and a district council pool. The company looks for large roofs with heavy daytime usage where it delivers most value.

The Hornby array is forecast to cut the school’s emissions by about 18 tonnes of CO₂-equivalent a year over 25 years – roughly the annual energy footprint of three New Zealanders, Conner said.

If the model proves itself on schools it could be rolled out across tens of thousands of suitable roofs, Conner added, from government offices to factories, using the existing hydro lakes as a “national battery” by dialling back dam output when rooftop solar is peaking.

Looking ahead, he wants the network of school arrays to double as a resilience asset.

Over the next five to seven years, COG hopes to start pairing rooftop solar with batteries at between 20 and 50 schools, turning them into civil defence hubs that can keep lights, heating and communications running after floods or earthquakes..

“If people can go to these schools and they have power, I’ll feel like that’s our little contribution to New Zealand Inc,” he said.