Australia’s electricity grid is creaking under the strain of an epic, two-week summer heatwave. Solar and demand management have helped minimize the impact after nearly two gigawatts of coal-fired generation fell off the system, but not before the disruption drove wholesale electricity prices up to the regulated maximum of A$14.50/US$10.30 per kilowatt-hour.
Reuters reported  late last week that “blistering heat triggered power outages on Australia’s strained grid on Friday as demand for air conditioning soared and coal-fired generators struggled to meet the surge in consumption.” New South Wales-based RenewEconomy put  temperatures in parts of the state of Victoria as high as 47°C, with overnight lows hovering around 30°C. The Australian Energy Market Operator (AEMO) instructed Alcoa Australia, Victoria’s biggest electricity user, to cut consumption at its Portland Aluminum smelter by 100 to 400 MW for just under two hours, then ordered rotating brownouts for up to 60,000 Melbourne households.
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“Coordinated supply interruptions are required to maintain electricity supply and protect the power system as Victoria deals with record-breaking high temperatures, high demand, and reduced generation availability,” AEMO said Friday afternoon.
“The record-breaking heatwave over the past week sent power prices soaring across southeastern Australia,” Reuters wrote. “Supply was tight, with a total of 1,800 megawatts (MW) of generation offline in the country’s east, AEMO Chief Executive Audrey Zibelman said on Australian Broadcasting Corporation TV. AGL Energy’s Loy Yang power plant and EnergyAustralia’s Yallourn, both in Victoria, were among those with units down.”
Zibelman, a former New York electricity regulator, urged consumers to cut their power consumption, while moving to quell fears of an outright blackout, Greentech Media reported . “The concern we always have is that when the system is under extreme pressure, the machines, really the generators and the networks, just like people, feel the discomfort,” she said. “They become stressed, and we have the possibility of additional outages. What we like to do in these situations is to make sure we have enough in reserve so that if we lose power plants, we have something to turn on.”
“The Australian energy system is coping with all this heat, but perhaps creaking a bit at the seams,” Victoria-based energy consultant Jill Cainey told Greentech. “It’s a bit of a challenge, as most of the National Electricity Market is experiencing high temperatures at the same time, so there’s a lot of air conditioning demand to supply, and it can’t be pinched from another load centre.”
In South Australia, 30,000 homes went without electricity Thursday after local power transformers overheated and switched off. “After days of heat, we were in some uncharted territory yesterday with record heat and record load sustained well into the night,” said SA Power Networks spokesperson Paul Roberts.
Victoria Energy Minister Lily D’Ambrosio attributed Australia’s longer, hotter, more extreme summers to climate change, the Reuters said. “We can see that the problem we’ve got now is that we’ve got a 20th century system for a 21st century climate,” D’Ambrosio told media.
In Adelaide, meanwhile, Greentech said fruit bats crashing into power lines had emerged as a major blackout threat. The heat has also had bats falling out of trees, but with no apparent impact on the electricity grid.
“None of this is a great outcome for consumers— and it’s safe to say it’s been a rough couple of days for AEMO,” RenewEconomy wrote. But the good news is how well the country’s “huge solar PV resource” was able to cut into peak electricity demand.
“Extreme heat leads to peak demand—it’s not news. But it also leads to peak solar generation – and that’s when the grid needs it most,” said Richie Merzian, director of the Australia Institute’s climate and energy program. “On Wednesday, you had rooftop solar shaving peak demand by over 2700 MW, more than an entire fully functioning, fully operational Liddell [coal-fired] power plant.”
RenewEconomy noted that rooftop solar reduced peak demand by just over 900 MW in Victoria, while solar and wind offset more than 1300 MW in South Australia.
“If you’re able to take more than 2000 MW off peak demand, that’s the difference between potential blackouts,” said Climate & Energy College analyst Dylan McConnell. “And it’s coming at a crucial time, when our system really benefits.”
David Evans, director of commercial and engineering at commercial energy retailer Flow Power, pointed to demand management as an even quicker way to bring relief to an overstressed grid.
Taking demand off the grid has the same effect of adding generation, which has the same effect of adding load. And through demand response it can be implemented very, very quickly,” he told One Step Off The Grid Editor Sophie Vorrath. Businesses and industrial users “are starting to understand that the market has very different pricing points depending on what’s happening,” he added, and “they can see that there is both an opportunity to save money and help out the grid. In essence, what you start transitioning to is a much more efficient market.”
But that hasn’t stopped Australia’s climate-denying federal government from proposing new coal-fired generation, or pro-coal interests from using the outages to support that plan.
“When the calls come in for more ‘baseload’ power, note that there are 10 ‘baseload’ units in the Latrobe Valley and today three of them are off for repairs,” tweeted Melbourne-based energy markets analyst Allan O’Neil in response. “More of the same would be the least sensible solution to a genuine reliability problem.”