$1 billion project delayed until end of 2026 due to equipment failure
A $1 billion “super battery” designed to ease Australia’s transition from coal to cleaner energy sources is facing further delays due to a major equipment failure, with its full rollout pushed back to the end of 2026.
The Waratah Super Battery, a sprawling complex the size of eight Australian Rules football fields located on the site of a former coal-fired power plant in Sydney’s north, was originally planned to be fully online by the end of 2025. But a “major internal fault” in one of its giant transformers during testing in October damaged vital equipment and delayed the planned launch of its remaining capacity until May 2026.
On Wednesday, the timeline for full operation was pushed back to seven months, the latest in a series of clean energy project delays that are prolonging NSW’s need to rely on coal-fired power plants and putting ambitious climate targets at risk.
Officials warn that grid-scale batteries that can store renewable energy are essential components of a greener grid because of their ability to provide rapid discharge when needed to plug urgent supply gaps and provide the specialized services needed to keep the system stable.
Earlier this year Origin Energy agreed to delay the closure of its Eraring generator in NSW, Australia’s largest coal-fired power station, citing the need to give the state more time to progress new generation, storage and transmission projects amid warnings from officials that the grid was not adequately prepared for the plant’s retirement.
The Waratah Super Battery is considered the flagship project of NSW’s energy transition strategy. Once at full speed, it will be Australia’s largest grid-scale battery and one of the most powerful battery systems in the world, with 850 megawatts of capacity and 1680 megawatt hours of storage, allowing it to run at full power for almost two hours. The system was originally designed to work like a “shock absorber” to protect the network from disruptions caused by events such as lightning strikes or wildfires.
But the battery’s owner, American asset giant BlackRock’s Akaysha Energy, said it was forced to delay its full increase in October following a “significant” internal failure of one of three transformers, critical parts of the infrastructure that raise voltage levels so electricity can travel safely across transmission lines. The company said the fault resulted in an “overpressure” event, which caused the tank wall to rupture and the transformer to leak into the environment.
It was stated that investigations into the cause of the malfunction are continuing.
Currently, only one of the three transformers is in service, and the battery operates with a capacity of 350 megawatts.
Akaysha told the market operator late last year that full commissioning of the fault would be delayed until May 2026, but on Wednesday it said the full capacity of the battery would now not come online until “end 2026”.
“The Waratah Super Battery continues to operate with a transformer in service,” Akaysha said in an update on Wednesday. “As a precautionary measure, the second transformer will be disabled.”
The project’s contractor, Consolidated Power Projects Australia, was instructed to replace the faulty transformer. Akaysha said that its manufacturer, Wilson Transformer Company, has started production and will deliver the replacement transformer to the field in the third quarter of 2026.
“The remaining capacity of the battery is planned to be commissioned by the end of 2026,” he said.
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Nick Toscano is an economic correspondent for The Age and the Sydney Morning Herald.Connect with: X or email.
