Thousands Of Melburnians Left Without Power
More than 145,000 customers are without power across Victoria as the state swelters through extreme heat, putting strain on the electricity system.
The Australian Energy Market Operator confirmed on Friday it had asked electricity distributors to "load shed" through the afternoon.
By mid-afternoon the blackouts by distributors totalled almost 150,000.
"It's all because, you know, we're balancing the weather, additional heat is stressing the generators," AEMO chief executive Audrey Zibelman said.
"We have one generator who has had some problems and they have been really struggling to stay on, but they're having to reduce to protect the machinery.
"Other generators are also struggling, simply because of the heat. So, it's all that in combination is what we're confronted with this afternoon."
Three generators, two at Yallourn and one at Loy Yang, had already failed in the lead up to the extreme heat, but a second unit at Loy Yang is expected to fail on Friday, Ms Zibelman said.
Power is being imported from South Australia to help Victoria cope.
Earlier on Friday, Victorian Energy Minister Lily D'Ambrosio had been assured by AEMO that there was enough power as temperatures reached beyond 40C across the state.
Friday's critical demand period will last until 5pm, before a cool change and the Alcoa aluminium smelter - the state's largest energy user - will go offline until the change sweeps the state.
About 10 other companies are also going offline to help the network.
Overnight minimum temperatures of 29.3C at Rutherglen was the northeastern town's hottest night ever since records began 100 years ago, Bureau of Meteorology senior forecaster Michael Efron said.
Suburban Essendon also recorded its warmest night in 17 years, at 30C.
On Friday, parts of northern and eastern Victoria will sizzle in the mid-40s, potentially breaking more records.
Melbourne CBD reached 42.3C at 2pm, but had rapidly dropped to 30.8C by 2.09pm.
Trains and trams were being speed limited across the city to allow for potential track warping in extreme heat.
A cool change is expected to have moved through the metropolitan area by about about 3pm, moving to the outer suburbs by 4pm, bringing a temperature drop of about 20 degrees within an hour.
But the change brings risk of rain, thunderstorms and dusty erratic winds and there is also a risk of dry lightning, which could spark more fires.
A total fire ban is in force statewide on Friday and a blaze has broken out in East Gippsland, with an emergency warning issued for Timbarra about 11am.
VICTORIAN POWER OUTAGES BY SUPPLIER
* AusNet 23,468
* CitiPower 28,418
* Powercore 61,032
* United Energy 32,090