Politicians lay blame after narrowly-averted power cuts highlight energy security issues

We were warned about power cuts and it was touch-and-go, but we got through the coldest day of the year without them - just.

Cuts and a grid emergency were avoided thanks to thousands of Kiwis doing their bit to reduce power use, along with industrial users dialling back demand and generators feeding as much electricity into the grid as possible.

Transpower has thanked New Zealanders for their efforts, but this morning's close call highlights a bigger issue with our energy security.

Record-cold May temperatures prompted a plea from Transpower for Kiwis to curb their power use - and the country stepped up to the challenge.

"They ultimately got us through what was a very tight part of the energy market this morning," said Energy Minister Simeon Brown.

Electricity demand peaked at 7:50am on Friday morning - Transpower says it almost dipped into the excess power supply it keeps as a buffer.

So why is our power system struggling to cope when it's not even winter yet? Well, it has to do with our transition to more renewable generation.

"Often cold is correlated with still times so it's colder and there's less wind, and we've been saying for some time as Transpower we need more fast-start capacity," Transpower CEO Alison Andrew said.

Transpower said that could mean gas-powered plants, or batteries, to fill sharp peaks when it's cold.

There's also the issue of dry years - since hydropower makes up around 70 percent of our electricity generation.

"Going forward, what are we going to do to replace that long-term deep storage? You need something big that can run efficiently for months," Andrew said.

Labour says the Government has not only stopped work on its Lake Onslow battery scheme, but also cut funding for other renewable storage options.

"It's gone back in to pay for tax cuts and it is putting New Zealand's energy security at risk. It is that kind of backwards thinking that is a real problem for New Zealand," Labour's energy spokeswoman Megan Woods warned.

But Brown said Labour scared off investors with its ban on new oil exploration, threatening energy security.

"That's why we've seen a 30 percent reduction in production just this year because we aren't having that upstream investment so we want to encourage that upstream investment," he said.

Meanwhile plenty of Kiwis are taking energy security into their own hands, like retired chartered accountant Mike Campbell, who's moving into a retirement village where he's installed solar panels.

He would love to see the Government help young people install solar and battery systems.

We asked the Minister if he'd consider that - and it doesn't look like it'll be happening any time soon.