AEMO chief executive Audrey Zibelman said she was confident the extra reserves would ensure Victoria avoided blackouts - although her agency is warning that conditions on Friday could also be extremely challenging. Loading Speaking on a day when AGL's massive coal-fired station at Liddell in NSW also suffered an outage, Ms Zibelman compared the nation's coal-fired power plants to ageing cars that break down more frequently over time. "Clearly as generators age, we are running them very hard and with the hot weather and the fact that the weather is getting hotter in Victoria, we’re running them more," Ms Zibelman said. "And so there is an expectation that like any old machines - think of old cars - that over time if you run them harder you are going to see more operating conditions that have to be fixed."

AEMO's decision to use its emergency reserves was part of its summer plan, preparing for the likelihood of generators losing capacity on hot days, Ms Zibelman said. "At this point we’re in a position where we anticipate that we have enough resources to get us through the peak; we are not going to be asking people to reduce their demand involuntarily," Ms Zibelman said. These reserves give us the ability to deal with these heatwaves, that's why we have this in our back pocket ... to mitigate the risk of supply shortfalls. AEMO's Audrey Zibelman "These reserves give us the ability to deal with these heatwaves, that's why we have this in our back pocket ... to mitigate the risk of supply shortfalls." Energy Minister Lily D'Ambrosio said Victorian summers were getting hotter and longer because of climate change and that this was putting more stress on the energy system.

"We know that we’ve got ageing brown coal generators here in Victoria and they are actually feeling the stress as we speak," Ms D'Ambrosio said. Winds were also light in Victoria with wind farms operating at around 35 per cent capacity and producing about 6 per cent of the state's output in the mid-afternoon. Mike Cannon-Brookes. Credit:James Alcock Australian tech billionaire and green energy advocate Mike Cannon-Brookes said AEMO should be commended for its efforts. "We should all thank AEMO for doing their best to manage an incredibly difficult situation with coal generation outages, high demand and extreme heat," Mr Cannon-Brookes said.

Mr Cannon-Brookes also took aim at supporters of new coal powered stations. Loading “The government supporting any more coal fired power stations being built is ridiculous idea - they’re unstable, expensive and toxic. This is just yet another brick in the wall of proof of that. It definitely strengthens the case for a smarter, faster, more responsive grid." Federal Energy Minister Angus Taylor said the current power shortages demonstrate the importance of the government's energy policy. "The conditions experienced over the last two weeks reinforce the need for investment in reliable generation," Mr Taylor said.

Illustration: Matt Golding Credit: "That is why the Government is backing in new reliable generation investment through its Underwriting New Generation Investments program and the Retailer Reliability Obligation." Businesses that have powered down previously include Bluescope's steel operations, OneSteel's Laverton and Whyalla steel mills, manufacturers Visy and Australian Paper, the Tomago smelter in NSW and Alcoa's Portland aluminium smelter in Victoria. Last summer, AEMO called on 1411 megawatts of backup power through this mechanism, at a cost of about $52 million. AEMO had earlier in the day stepped back from its prediction that the lights could go off in Victoria in the early evening and in the afternoon warned Friday now looked like a more critical problem.

Loading Replay Replay video Play video Play video In the mid-afternoon the operator forecast a potential blackout around midday Friday unless it is able to immediately obtain additional power. It is forecasting the need for least 800 additional megawatts to meet its minimum reserve for Friday for the rest of the day. Even as Victoria attempted to balance its tight power supply and demand levels, it still intermittently exported energy to New South Wales. Some towns in central Victoria experienced blackouts on Thursday, related to failures of their local poles and wires company rather than the generators.