Australia, New South Wales: Australia’s most powerful battery project will remain below full output for much of the year after the failure of a key transformer, with a replacement now expected in the second half of 2026.
Akaysha Energy, owner of the Waratah Super Battery in New South Wales, said one of the site’s transformers suffered a “significant internal fault” in October 2025. The fault caused damage to the windings and an overpressure event that ruptured the transformer tank wall, leading to the unit self-draining into a contained area. Investigations into the cause of the failure are still ongoing.
The incident occurred as the 850 MW / 1,680 MWh battery, located at the former Munmorah coal-fired power station site, was nearing completion of final testing ahead of full commissioning. The project had already faced delays of at least six months, largely attributed to adverse weather.
Akaysha said production of a replacement transformer is now under way, with Australian manufacturer Wilson Transformer Company beginning work after securing long-lead components. Delivery is scheduled for the third quarter of 2026.
Until then, the battery will continue operating with only one transformer in service. A second transformer remains offline as a precaution and will be addressed as part of a defined remediation programme, with the aim of having all three transformers operational later in 2026.
As a result, Waratah is currently delivering around half of its contracted System Integrity Protection Scheme capacity, operating at about 350 MW / 740 MWh. The battery continues to be used by the Australian Energy Market Operator to support grid stability and help prevent blackouts during periods of high demand or generator outages.
Akaysha said the use of a local transformer supplier has helped speed up engineering reviews, site works and manufacturing preparations, and it will provide further updates as the project progresses.
Source: Renew Economy
