12 Dec 2017

Hot weather bad omen for winter power supply - scientist

9:56 am on 12 December 2017

A climate expert is warning a downside to the brilliant early-summer weather is the effect it could have next year on electricity supply.

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A climate scientist says the dry conditions are a worry for electricity supply but Genesis Energy says it's too early to make a call. Photo: 123rf

New Zealand usually has a wet spring and early summer which fill hydro storage dams to the brim, with plenty left over for the electricity-hungry winter.

But this year, that has not happened, with a hot and dry spring for much of the country

Victoria University climate scientist James Renwick said this could be a worry.

"We often see higher flows at this time of year and into the summer, replenishing the lakes," Dr Renwick said.

"So dry conditions at this time of year is not a good sign.

"If things do continue [to be] dry into the summer, that does not set us up well for going into the next winter."

But electricity companies say it is way too soon to make a call about winter conditions that are still six months away.

Tracey Hickman from Genesis Energy said steps had already been taken to preserve water for generating electricity in future.

"Our thermal power stations, particularly at Huntly, are running reasonably hard," she said.

"That just provides back up to that hydro storage.

"We run both coal and gas and it depends on any one day as to which of those fuels we burn."

The most recent figures show gas and coal produced 23 percent of New Zealand's electricity in the past week, compared with a 15 percent average.

Ms Hickman said she thought that was prudent, and her company was already talking to others to prevent shortages come winter.

"Winter is a way away yet, so it is too soon to start worrying about it, but there are plenty of incentives in this industry to keep a close eye on it.

"We do have thermal backup when we need it to support low hydrology.

Greenpeace's Amanda Larsson said it showed weather patterns like the current one could damage the environment.

"These fossil fuels are being fired up on some of our hottest and sunniest days, which would be most suited to solar power," she said.

"So it is really a matter of more investment in clean energy to resolve the fact that climate change is going to put a lot of pressure on our hydro lakes."

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