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<\/p>\nOn Wednesday, as the temperature soared into the 40s across large parts of southern Australia, the country’s biggest electricity market stayed eerily quiet.<\/p>\n
Spot prices \u2014 a key sign of the balance between supply and demand across the national electricity market serving Australia’s eastern seaboard \u2014 were subdued.<\/p>\n
The Australian Energy Market Operator, which keeps the lights on across the NEM, was issuing few warnings about the risks to supply.<\/p>\n
Read more about heatwaves in Australia:<\/p>\n
And the commentators and pundits so attuned to the vagaries of the electricity system were somewhat muted beside their keyboards.<\/p>\n
Geoff Eldridge, an electrical engineer who runs consultancy Global Power Energy, said the whole episode was striking for what was not happening.<\/p>\n
“Hot summer days have long been a stress test for electricity systems,” Mr Eldridge wrote in a post on Substack.<\/p>\n
“High temperatures drive demand upward, air-conditioners run hard and supply margins are scrutinised closely.<\/p>\n
“This week’s heat has again pushed demand toward record levels.<\/p>\n
“Yet the system response has looked noticeably different.<\/p>\n
“There were no Lack of Reserve notices, no calls for emergency reserves, and prices were largely stable through the middle of the day.”<\/p>\n
Australia’s biggest grid has held up remarkably well in the heatwave. (ABC News: Andrew O’Connor)<\/p>\n
Heatwave a turning point<\/p>\n
Mr Eldridge said this week’s heatwave marked a turning point for Australia’s energy transition.<\/p>\n
In the past, he said extreme heat “placed continuous pressure on supply throughout daylight hours”.<\/p>\n
To ensure supply, coal and gas plants had to “run hard from morning until evening, with little respite”.<\/p>\n
As recently as 2019, during another heatwave, he said this historic precedent was largely true.<\/p>\n
But he said the events of this week \u2014 when underlying demand surged to a record high of more than 40,000 megawatts \u2014 suggested that picture was now fundamentally changed.<\/p>\n
The pounding sun was no longer a liability, he said, but rather an asset.<\/p>\n
“Looking across recent summers, the most notable change is not that demand has eased \u2014 it has not,” he wrote.<\/p>\n
“Peak [underlying] demand is higher than it was in 2019, and summer heat remains a defining challenge.<\/p>\n
“What has changed is how the system absorbs that challenge. Solar now carries much of the heat-driven load during the day.”<\/p>\n
Indeed, solar at its height on Wednesday was providing more than 60 per cent of the power being used in the NEM.<\/p>\n
About two-thirds of that was coming from rooftop solar installations.<\/p>\n
Combined with wind and hydropower, solar met as much as 76.6 per cent of demand on the day.<\/p>\n
Almost half of all supply over the 24 hours came from renewable sources.<\/p>\n
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More than one in three Australian homes now has solar panels. (ABC News: Jess Davis)<\/p>\n
It’s a far cry from just seven years ago, when renewable energy at no stage provided more than 26 per cent of supply during a separate heatwave.<\/p>\n
Such is the periodic abundance of renewable energy in 2026 \u2014 especially from solar \u2014 Mr Eldridge noted it could have actually produced more but for “curtailment”<\/a>.<\/p>\n This refers to the practice of throttling back or switching off generators because of insufficient demand or technical requirements.<\/p>\n Winter, not summer, the risk<\/p>\n Bruce Mountain from the Victoria Energy Policy Centre said the significance of the shift was hard to overstate.<\/p>\n In essence, he said the explosive growth of solar power in particular had diminished the risks of blackouts during heatwaves caused by supply shortfalls.<\/p>\n Bruce Mountain says the grid is now under more strain in winter. (ABC News: Sean Warren)<\/p>\n By contrast, he said the risks were now becoming much more severe in winter, when demand for electricity can be extremely high but output from solar is much lower.<\/p>\n “I think summer peak daily production, other than in evening hours, has become a complete non-issue,” Mr Mountain said.<\/p>\n “We’re increasingly moving to at least full grid supply winter peaking system when solar is low and demand is relatively high.<\/p>\n “I’ve seen this over the last three or four years \u2014 much more of the strain is happening in winter than in summer now.”<\/p>\n Despite the improved outlook for the grid in summer, Mr Mountain said big risks remained.<\/p>\n For starters, he said, while solar power helped take much of the sting out of daytime supply concerns, it was much less helpful in the evening.<\/p>\n He also said the critical time for power grids during summer in Australia was typically from late January, once schools had resumed and industry was back up and running.<\/p>\n “So after the 25th of January, if you have three or four days of 40-degree temperatures in Victoria and other states \u2026 that’s the time to look,” he said.<\/p>\n What’s more, Mr Mountain said the apparent ease with which the market sailed through the heatwave this week was still thanks in large part to coal plants.<\/p>\n![\"a](\"https:\/\/www.newsbeep.com\/au\/wp-content\/uploads\/2026\/01\/6266037b857a9a0c5183c4e65df6dc33.jpeg\")
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