Octopus Australia to build Australia’s largest battery project

Accelerating its plan to directly replace retiring coal fired power plants with a reliable and strategic portfolio of renewable energy sources, Octopus Australia has acquired the Hanworth battery energy storage system (BESS) in New South Wales (NSW), as well as the Dunmore solar farm and battery project in Queensland.

At full scale, the 1.2 GW/4.8 GWh Hanworth BESS, located near Bannaby, west of Bowral in NSW, will be capable of storing and delivering enough electricity to power more than half a million homes during the evening peak, when demand is highest and solar generation drops off.

The solar-battery development at Dunmore in Queensland will act like a hybrid engine, combining a 300 MW solar farm with a 150 MW/300 MWh battery system, soaking up surplus energy generated through the day and releasing it in the evening, when demand surges.

With around 75% of Australia’s coal-fired power stations due to retire within the next nine years, the task of delivering large scale replacement supply has become a national priority. Octopus Australia’s investment strategy reflects the International Energy Agency (IEA)’s assessment that power systems will only remain reliable if clean generation is backed by assets that are flexible and can respond quickly and stabilise the grid. In line with the IEA’s World Energy Outlook 2025, Octopus Australia is investing in firmed renewable capacity – including large scale batteries, hybrid solar and storage projects, flexible generation, and community-integrated infrastructure – to turn low-cost renewable power into dependable electricity customers can rely on. That is the shift now underway in energy markets, and it is exactly where Octopus is positioning its capital – in the infrastructure that makes clean energy work in practice.

The Hanworth project has been acquired from Australian energy developer, Enervest, connecting into Transgrid’s Bannaby Terminal Station. It will support long-term electricity supply contracts for large customers seeking firmed renewables, helping to facilitate the provision of low-emissions power at stable prices.

The Dunmore solar and battery project near Toowoomba in Queensland has been acquired from Samsung C&T Renewable Energy Australia (SREA) in the company’s first renewable energy transaction in Australia, marking an important industry milestone. The transaction reinforces Octopus Australia’s reputation as a partner of choice for global energy companies and builds upon a growing portfolio in Queensland which includes a host of solar and battery projects across the state.

The acquisitions come at a time when new renewable energy investment across Australia has slowed. However, Octopus Australia is continuing to build at scale, supported by the success of its portfolio model. Unlike single projects that depend on one weather condition, Octopus Australia combines solar, wind, and batteries across multiple sites so energy can be shifted to where and when it is needed. Octopus Australia owns 100% of these assets, making it agile in its ability to match supply with energy demand and doing so without the commercial friction that impedes others in the market where assets have multiple direct owners.

This approach allows Octopus Australia to supply customers with firm, predictable power, while reducing exposure to price spikes in the wholesale electricity market. Octopus Australia counts some of the largest and most sophisticated institutions among its investors base, including the Australian Government (the Clean Energy Finance Corporation and state government entities), APG pension fund (largest pension manager in Europe), large Australian superannuation funds (Rest and Hostplus – both with AUS$100 billion of assets under management) and wealth managers (Westpac Private Bank).

Octopus Australia CEO, Sam Reynolds, commented: “While some investors are stepping back, we’re stepping forward. 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. This is about replacing coal with clean energy that works in the real world.”

Enervest CEO, Ross Warby, added: “This transaction with Octopus Australia represents a landmark outcome for Enervest, reflecting both the strength of our development portfolio and the significant investment and work completed to date. Partnering with a reputable, long-term partner like Octopus enables us to realise value from Hanworth while sharpening our focus on Enervest’s own-and-operate strategy. We believe Octopus is well-placed to accelerate this asset to meet growing demand, and we look forward to seeing the benefits it will bring to the local community, the grid, and the broader energy transition.”

A SREA spokesperson concluded: “Dunmore is a high-quality project in a strong location, and we’re proud of the progress and outcomes delivered so far. Following the progress achieved to date, the project is set to move into its next phase under Octopus Australia, a long-term investor with the capability to deliver it, and we look forward to seeing it contribute to Australia’s future energy supply.”

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