Waratah Super Battery completes, letting NSW lines carry more power safely
Serguey Asael Shinder2 min readAkaysha Energy has reached final commercial operation at the Waratah Super Battery in New South Wales, Energy-Storage.News reported on 28 September, closing out a commissioning period that ran through a transformer failure and months at reduced capacity. At 850MW and 1,680MWh, built on the site of the former Munmorah coal power station, it is the most powerful battery in Australia.
What makes Waratah a grid story rather than just a storage one is the System Integrity Protection Scheme (SIPS) built around it by Transgrid, the state's transmission operator. The control system monitors 36 transmission lines in real time. If a disturbance occurs, Transgrid can signal the battery to inject energy while instructing paired generators to adjust their output. That fast response lets existing lines serving the Hunter, Sydney and Illawarra regions carry more power than they otherwise could, as a stopgap until the Hunter Transmission Project connects inland renewable energy zones. The project was commissioned by the NSW government through its EnergyCo procurement.
The path was not smooth. Waratah first discharged its full 850MW on 10 October 2025, but the same month a high-voltage transformer suffered what was described as a catastrophic failure; a second was taken offline as a precaution, leaving the site at 350MW. A replacement from a domestic manufacturer avoided the 12-to-18-month lead times typical of imported units, and the battery returned to 700MW in June, with 350MW committed to the SIPS contract. The original battery supplier, Powin, went through Chapter 11 during delivery, with its assets and servicing taken over by FlexGen.
What it means
Transmission is the slowest part of the energy transition to build. A protection scheme like this turns a battery into a substitute for new wires: lines can be run closer to their limits because something fast is standing by to catch a fault. It is a stopgap by design, until the new transmission arrives, but a stopgap measured in years.
The transformer episode is the other lesson. Specialised grid equipment is a bottleneck in its own right, and the decision to buy domestically to cut lead times is one other projects are likely to copy.