Image: Akaysha Energy
The Waratah Super Battery, Australia's largest grid scale battery, briefly reached its full rated output of 850 megawatts on 7 September, according to data from Open Electricity. It is the first time the facility has hit full output since a transformer failure cut its capacity for most of the past year.
A shock absorber for the grid
Built on the site of the former Munmorah coal fired power station on the NSW Central Coast, the 850 megawatt, 1,680 megawatt hour battery is owned by Akaysha Energy and contracted to transmission operator Transgrid. It acts as a giant shock absorber that lets existing transmission lines into the Hunter, Sydney and Illawarra carry more power than they otherwise could.
A year of reduced output
- October 2025: first full 850 MW discharge, followed by a transformer failure
- June 2026: second transformer returns, capacity restored to 700 MW
- 7 September 2026: facility briefly reaches full 850 MW output again
The replacement transformer was built domestically by Wilson Transformer Company, avoiding the long lead times of overseas units. With all three transformers in place, the facility is completing the testing needed to certify it for ongoing full capacity operation.