Half a million households in Victoria are without electricity and trains have been suspended across metropolitan Melbourne after a power station went down during storms.
Victoria’s energy minister, Lily D’Ambrosio, has confirmed about 500,000 households were without power late on Tuesday afternoon after two transmission towers collapsed near Anakie, north of Geelong, causing Loy Yang A power station to trip and go offline.
D’Ambrosio said she had met with the Australian Energy Market Operator’s. (Aemo) chief executive, Daniel Westerman, to discuss “the current unprecedented impact of extreme weather on Victoria’s power grid”.
“Due to the physical collapse of some transmission lines caused by this severe weather, many Victorians are currently without power,” she said.
“We are working with Aemo and relevant authorities to get Victorians back online as quickly as possible and we want to thank those impacted for their patience.”
The storms, which brought heavy hail and strong winds to Victoria and saw the temperature plummet 15 degrees, also wreaked havoc on the state’s public transport system, with half of the Melbourne’s 16 metropolitan train lines partly suspended as commuters began to make their way home from the CBD.
Services were moved onto replacement busses on the Alamein, Belgrave, Craigieburn, Cranbourne, Frankston, Glen Waverley, Lilydale, Pakenham and Sunbury lines throughout Tuesday afternoon.
V/Line services were also suspended on sections of the Gippsland, Seymour and Shepparton lines and replaced with buses.
Delays of more than 60 minutes were expected across the public transport network.
Public Transport Victoria warned passengers should allow extra time for their journey, and “consider alternative travel plans, such as altering your departure time, or using a different mode of public transport”.
Loy Yang A power station is one of Victoria’s three remaining coal-fired plants and, when fully operational, has a maximum capacity of 2210MW.
A spokesperson for its operator, AGL, said a transmission line failure prompted all four units at Loy Yang A to drop offline at 2.15pm.
In another statement just before 6pm, they said AGL will continue to work with Aemo and stakeholders to investigate the cause of the issue.
“Following today’s tripping of transmission lines that led to the unplanned outage, work is underway to return units back to service,” the spokesperson said.
“This will take place over the next few hours in line with our safety and operational protocols and as associated transmission line issues are resolved.”
It is expected Unit 1 will remain offline, but units, 2, 3 and 4 will be brought back online in line with safety protocols progressively through the evening.
At the time of the outage, Victorian wholesale power prices increased to $16,600 per megawatt hour, compared to $60.39 in Queensland and $299.98 in NSW.
Aemo issued a market alert declaring a “significant” power system event because of “multiple tripping of generation and transmission lines” in Victoria about 4pm.
They said they would would beginning load shedding, or switching customers off due to a lack of supply, in Victoria.
“To keep the power system secure, Aemo has directed AusNet Services to enact load shedding,” they said.
“Controlled load shedding is a mechanism Aemo uses as an absolute last resort to protect system security and prevent long-term damage to system infrastructure,” he said.
The failure has resulted in 2,300MW of generation being halted, with more than 1,000MW of load interrupted.
Later on Tuesday, Aemo said all 90,000 customers who were switched off have had had their electricity restored.
They said the power outages were are due to high temperatures, strong winds and lightning causing damage to the electricity network.
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Dylan McConnell, an energy expert at the University of New South Wales, said significant incidents in the grid were “very infrequent”.
Bruce Mountain, head of the Victoria Energy Policy Centre, said power demand in the state was fluctuating with the Portland aluminium smelter dropping offline, returning, and apparently exiting again.
Power supply issues may extend to South Australia later on Tuesday. “They depend critically on Victoria in the evening,” Mountain said.
“It’s going to be a nervous evening” for many power consumers in Victoria and South Australia, he said.