New Zealand set a new record of renewable electricity use in the June quarter.
Figures in the New Zealand Energy Quarterly show 91% of electricity in that three-month period was generated by renewable means such as hydro, wind and geothermal.
The long-term average for renewable electricity is around 85%.
“This is the highest renewable (number) for any June quarter since records began in 1980,” says Mike Hayward, a senior official at the Ministry of Business, Innovation and Employment (MBIE).
“Hydro generation was up by 25.2% on the June 2022 quarter, while coal generation was down 71.7% and gas generation was down 45.7%.”
These developments follow a policy of the current government’s that the electricity sector should aim to have its product 100% renewable by 2030.
However, expert consensus would indicate these figures do not constitute any real victory. Climate change experts have warned repeatedly that the weather will be highly variable under emerging environmental conditions. That means the well-documented deluges of the past nine months might not be replicated in the next nine months, so hydro dams which are full this year might be empty next year.
There have been multiple warnings about New Zealand’s electricity vulnerability even under current conditions of windy weather and heavy rainfall. These came from Transpower in May, again in June and for a third time in August. In addition, several energy groups wrote to all main political parties last month saying consistent energy policies are vital for economic progress.
The thrust of their arguments was that renewable electricity is desirable but not reliable on its own, because the weather can change quickly, leaving wind turbines idle and hydro dams empty. But back-up systems, such as the Huntly power station, are not always nimble enough to fill in the gaps in quick time.
A week ago, an umbrella group, Energy Resources Aotearoa, published a warning that New Zealand was still exposed to risk, saying the danger of electricity shortages has actually increased since Transpower’s first warning.
Its executive John Carnegie, says the worries issued a week ago still stand. That is despite his approval of the MBIE data in principle.
“It’s fantastic that we are reaching such high levels of renewable electricity, but that does not obviate the need for thermal back up,” he says.
“And those numbers do not speak to half hour by half hour availability of electricity, which is what we are concerned about.”
Carnegie says having insufficient thermal back up means the system is exposed to potential shortages of electricity.
He says fast-acting gas-fired peaking plants are the best way to go. The Huntly power plants by contrast take too long to warm up, so by the time they are fully operational, a windfarm can have shut down, and started up again, as a spell of calm weather passes.
The Minister of Energy and Resources Megan Woods was approached for comment on this story.
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