55,000 left without power in 45-degree heatwave as Melbourne’s energy demands break records

Extreme heat and bushfire damage led to mass power outages across Melbourne’s eastern suburbs yesterday, with more than 55,000 left in the dark for hours across the state’s east.

What happened: According to energy network operator AusNet, about 55,000 customers from areas across the eastern and north-eastern suburbs – including The Basin, Lilydale and Ringwood – lost electricity supply at about 10pm on Tuesday evening.

• As of about 9am on Wednesday morning, 12,500 customers remained powerless due to 187 unplanned outages.

Broader impacts: Energy, Environment and Climate Change Minister Lily D’Ambrosio said power outages across the state peaked at more than 100,000 due to bushfires burning out electricity assets, strong winds causing trees to fall on poles and wires, and heat-related equipment failure.

• The Australian Energy Market Operator (AEMO) said the state had “sufficient energy reserves to meet demand”. 

• Typically, operational demand is about 3,700 to 5,000 megawatts. On Tuesday, Victorians turning on air conditioners and other appliances after returning home from work drew 10,567 megawatts. 

Fires still burning: Multiple bushfires are burning across the western region of Victoria, with the Gellibrand-Carlisle River fire having now burnt through more than 11,000 hectares and destroyed three homes as containment lines were breached over the weekend.

• More than 1100 residents in the Colac Otway Shire have been ordered to evacuate their homes since Monday evening, and more than 120 people have taken shelter in relief centres as of Tuesday afternoon.

• Communities in the state’s north-east are tallying the damage sustained in the Longwood fire – which burnt through about 136,000 hectares – and the Walwa blaze – which covered more than 100,000 hectares.

How hot did it get? Victoria broke its record for the hottest temperature ever recorded on Tuesday, with Walpeup in the state’s north reaching 48.9 degrees.

• Parts of Melbourne breached the 45-degree mark, while Melbourne Airport hit 44.1 degrees.

• According to the Bureau of Meteorology’s 2025 preliminary summary, Australia experienced its fourth-warmest year on record last year, with temperatures 1.23 degrees above the 1961-1990 average.

What caused the mass outages? An AusNet spokesperson said extreme heat was the major cause of the outages.

• 🗣️ “The extreme weather damaged substations and fuses across various components of our network,” said the spokesperson. “The most impacted areas are the eastern suburbs of Melbourne and in the central and north-east of the state. AusNet crews have been working throughout the night to bring customers back online.”

• Overall warming reduces the amount of power that can be carried by transmission lines to avoid damage from overheating and to limit sagging, as hotter conditions cause the metal electrical conductors – often aluminum or copper – to expand and lengthen.