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Akaysha Energy has confirmed a planned balance-of-plant shutdown of the 850MW Waratah Super Battery from 20 November to 2 December 2025 to replace a failed transformer. The incident follows a catastrophic transformer failure in October that reduced the facility’s operational capacity from 850MW to 350MW.

As we previously reported in our coverage titled “Australia’s Largest Battery Faces Setback After Transformer Failure”, the transformer issue has delayed full commissioning of the battery, which was designed to be the world’s largest battery energy storage system. Despite the failure, the battery continues to provide System Integrity Protection Scheme (SIPS) services.

Dr Tom Harries, partner at NARDAC, estimates losses from the transformer failure could range between US$32–51 million (AU$50–80 million) . The final amount depends on the speed of transformer replacement and potential coverage under delay-in-start-up insurance.

Main power transformer replacement typically requires 12–18 months lead time due to specialized manufacturing needs. However, the transformers were produced by Australian manufacturer Wilson Transformer, allowing diagnostics, repair, and re-commissioning to be handled locally, potentially reducing turnaround times.

Located at the former Munmorah coal-fired power station near Budgewoi, the Waratah Super Battery monitors 36 transmission lines in real time and responds within seconds to grid disturbances, acting as a “giant shock absorber” for Australia’s National Electricity Market (NEM).

Nick Carter, CEO of Akaysha Energy, described the incident as a “catastrophic failure” and emphasized the importance of replacing the transformers to restore full capacity. The battery is expected to return to its designed 850MW capacity during 2026.

The scheduled shutdown coincides with increasing summer electricity demand, highlighting challenges in managing renewable energy intermittency across the NEM.

Source: energy-storage.news