Photo: FREELANCEIMAGES/UNIVERSAL IMAGES
A long list of 147 solar, wind and geothermal projects have been announced by companies eager to find investment for a renewables boom.
Massey University mathematics professor and climate writer Robert McLachlan said if every solar or wind farm that was announced got built, New Zealand would be flush with renewable energy.
The Electricity Authority's generation pipeline said 10,000 gigawatt hours of new supply were being actively pursued out to 2026, equal to between a quarter and a fifth of the country's annual power consumption.
But McLachlan said less than a fifth of that was fully committed or close to committed before the end of next year.
"In the short term there will be more projects approved.
"I don't think there's enough for next year," he said.
Wholesale prices looking forward suggested shortages may happen again next winter, especially if it was another dry one for hydro dams, he said.
"There is an enormous pipeline of possible projects, like stupendously large, the question is, is the market structured so enough of them will actually be built."
After over a decade of very little new generation, a boom since the start of 2023 saw enough renewable electricity added to power 7 per cent of the country's consumption.
This winter's stretched market would have been worse if those new renewable plants were not built, to take some of the pressure off, McLachlan said.
Rooftop solar installation on individual buildings also doubled in the previous year.
"We're just seeing the first solar farms fully built and operating, they are getting bigger and there are new companies coming in, like Lodestar Energy, so that's really good," he said.
"Those projects that got the go-ahead in the early 2020s are just being finished now so we're seeing a huge wave of construction."
The question was whether the boom would keep going at the current pace.
The Mt Cass wind farm looked certain to happen but was now on hold, while the fossil-fuelled Statford gas power station had its life extended until at least the end of this year, until more renewables were ready.
Singapore-owned Ranui Generation has just started building a solar farm south of Kaitāia - Northland's third significant solar farm.
Chief executive Jason Foden said the company had big plans to follow Kaitāia.
"We've got two in Taranaki that are running quite close together, we're expecting to start those in Q2 next year, we have another one in central Hawke's Bay. We expect that would be next the end of year when we would start that one ... we're also interested in developing wind and also may some biomass as well."
Photo: RNZ/Sally Round
But Foden said there were barriers that needed to be cleared, even aside from working out whether the price and demand for electricity were high enough to make a good return.
"We need more lines upgraded and we need more points of entry into the network," he said.
"The other issue is consenting, so communities do need to have their say and particularly we see consenting take a long time for wind farms.
"And then there's investment, like the first project was a $40 million investment. That money's got to come from somewhere, and when it comes from overseas then it has to go through the Overseas Investment Office, because there's land involved."
The government-owned Green Investment Fund plans to help with one of these hurdles.
Having already started a $350 million solar finance fund, chief investment officer Jason Patrick said the next fund would finance the poles, wires, transformers and other kit needed to connect to new renewables to the grid.
The first project was connecting Far North Solar's new solar farm.
"Really in order to attract the big global investors you've got to have something that's more than $100 million, really ideally $200 million dollars," he said.
"Solar finance was just an idea a couple of years ago and now it's a $350 million programme.
"This first connection asset deal with Far North [Solar] was $70-$80 million investment and once we have several of those we will start bringing in those global investors."
Electricity demand is expected to grow with EVs, electrification of industry, and data centres. Grid-scale batteries like a new one at Huntly are being built to store power when the sun and wind are strongest for use on cold evenings, when demand peaks.
Depending on the outlook for electricity prices, it could be worth building smaller batteries at solar farms such as Ranui's one in Northland, Foden said.
But that would depend on the region having an oversupply of electricity during the day, something it did not have currently, he said.