

EXECUTIVE SUMMARY
Construction has been approved for Origin’s 300 MW/650 MWh Mortlake Battery Energy Storage System in Victoria. Located beside the Mortlake Power Station and within the South-West Renewable Energy Zone, the battery is expected to be commissioned in late 2026 and support renewable integration and grid stability.
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Australian energy provider, Origin Energy has approved construction of the Mortlake Battery Energy Storage System (BESS), a 300 MW project capable of delivering up to 650 MWh of energy storage in Victoria, Australia. The large-scale battery will be developed next to Origin’s Mortlake Power Station, which has a generation capacity of 566 MW and is Victoria’s largest gas-fired power generator.
The site is located adjacent to the Moorabool–Heywood 500 kV transmission line and within Victoria’s South-West Renewable Energy Zone (REZ). Western Victoria already hosts several operational renewable energy generators, while additional renewable energy developments are expected within the South-West REZ.
The Mortlake BESS is expected to be commissioned in late 2026. Once operational, the battery will charge during periods when renewable electricity from sources such as solar and wind is plentiful. Stored electricity can then be discharged into the grid during peak-demand periods.
According to Origin, the system is intended to support further renewable energy development while providing firming capacity and stability to the National Electricity Market. Large-scale batteries are increasingly being used to manage variations in renewable generation by shifting electricity between periods of high generation and higher demand.
The project has received funding from the Australian Renewable Energy Agency (ARENA) under its Advancing Renewables Program.
Alongside construction of the BESS, Origin is operating a community investment program for communities around the project. The Mortlake Battery Energy Storage System Community Investment Program targets community wellbeing, community resilience, economic development and environmental initiatives.
Applications can seek funding of up to AUD 10,000 for eligible events and activities. Initiatives delivering measurable community outcomes within the Moyne and Warrnambool local government areas are encouraged to apply. Origin said priority will be given to projects designed to provide sustainable and enduring benefits beyond the funding period.
The battery adds energy storage infrastructure alongside the existing Mortlake generation and transmission assets, with its location providing access to renewable generation within western Victoria and the wider National Electricity Market.