With three-quarters of Australia’s coal-fired power plant fleet set to retire by 2030, Australia’s state governments and investors are increasingly deploying grid-scale battery projects to deliver firm capacity, integrate renewables and help stabilise electricity prices.  

The most recent to come onstream is Synergy’s Collie BESS (CBESS) project, located 200 km south-east of Perth, opposite the 350 MW Collie power station, which is due to close in 2027. With a 2,400 MWh storage capacity, the four-hour duration system is the largest currently operational BESS in Australia. Neoen’s 2,240 MWh BESS, also located in Collie and commissioned last year, held the record previously.

According to state-owned Synergy, the CBESS project is central to the Western Australian state government’s Energy Transformation Strategy, which aims to deliver at least 6.5 TWh of new wind/solar projects and 1.1 GW of storage by 2030.

CBESS is the third grid-scale battery delivered by the state in just over three years. Western Australia now has more than 3,500 MWh of storage capacity installed across its South West Interconnected System (SWIS).

Premier Roger Cook commented: ‘This is a milestone moment in Western Australia’s energy transition… This battery is a key part of the state government’s delivering on Western Australia becoming a renewable energy powerhouse.’

Energy & Decarbonisation Minister Amber-Jade Sanderson, added: ‘Renewable energy is the cheapest form of power. Synergy’s batteries capture excess wind and solar power for use when it’s needed. This makes more cleaner, cheaper energy available for Western Australians. These batteries back more wind and solar generation to enter the system and supports our plans to exit state-owned coal generation by 2030, which together will put downward pressure on electricity prices.’

The state’s utility-scale rollout complements its A$337mn ($238mn) WA Residential Battery Scheme, which has already supported more than 10,000 households to install behind-the-meter storage. Funding is available for up to 100,000 installations, aimed at delivering bill savings while strengthening system resilience from the bottom up.

Octopus Australia lines up 4.8 GWh flagship in NSW

On the east coast, private capital is moving at comparable speed, with Octopus Australia acquiring the Hanworth BESS in New South Wales (NSW) and the Dunmore solar-and-battery project in Queensland.

At full scale, the Hanworth project near Bannaby, west of Bowral, will reach 1.2 GW/4.8 GWh – taking over from Synergy’s CBESS as the largest battery in the country. Acquired from Enervest, it will connect into Transgrid’s Bannaby terminal station. According to Octopus, the project is expected to underpin long-term electricity supply contracts for large customers seeking firmed renewables, facilitating low-emissions power at stable prices in a market often characterised by volatility.

In Queensland, the Dunmore development near Toowoomba combines a 300 MW solar farm with a 150 MW/300 MWh battery. It was acquired from Samsung C&T Renewable Energy Australia (SREA).  

Octopus Australia CEO Sam Reynolds framed the investments as a structural shift rather than a niche play. ‘Australia still needs new power stations to replace ageing coal plants. The difference is that today we can build them using a mix of solar, wind and batteries instead of smokestacks. By owning and operating our projects as one portfolio, we can deliver reliable power every day of the year – not just when the sun shines or the wind blows.’

Iberdrola and FRV secure long-term backing in NSW

Meanwhile, Iberdrola has been awarded a long-term contract for the 100 MW Kingswood battery in NSW and has officially opened its 65 MW Smithfield facility in western Sydney.

Kingswood will provide 1,080 MWh of storage, enabling it to discharge for at least eight consecutive hours and supply around 65,000 homes at peak demand. The project has secured a Long-Term Energy Service Agreement (LTESA) under the sixth auction round of the NSW Electricity Infrastructure Roadmap.

The LTESA framework is designed to provide revenue certainty for investors while delivering competitive prices for consumers. Operating as a form of insurance against wholesale price volatility in the National Electricity Market (NEM), the agreements are awarded through competitive tenders run by the Australian Energy Market Operator (AEMO).

Smithfield, with 130 MWh of storage, was completed ahead of schedule and secured its LTESA contract in round two of the same programme.  

Iberdrola says both projects will strengthen renewable integration, increase grid flexibility and improve overall system efficiency and security.

Fotowatio Renewable Ventures (FRV) Australia has also secured an LTESA for its proposed Armidale East BESS project under round 6 of the NSW Roadmap. Located 16 km east of Armidale, the project will deliver 315 MW of capacity, with 157.5 MW configured for an eight-hour duration system.  

The development supports NSW’s legislated long-duration storage targets of at least 16 GWh by 2030 and 28 GWh by 2034, says FRV.

Victoria fast-tracks 700 MW of new capacity

In other developments, the state of Victoria has greenlit Atmos Renewables’ 300 MW BESS in Heywood and Akaysha Energy’s 400 MW BESS in Glenrowan under the state government’s Development Facilitation Program (DFP), a streamlined pathway intended to fast-track renewable and storage projects.

Since the DFP was expanded to include renewable energy projects less than two years ago, the state says it has unlocked more than A$9bn in investment across 25 projects, creating more than 3,300 construction and operations jobs. Once completed, the approved projects are expected to generate enough electricity annually to power more than 735,000 households. Their battery components will collectively be capable of meeting peak demand for around two million homes, according to the state government.