Ex-Macquarie Bankers Unveil Giant 4,800 MWh Battery: Australia’s Next Big Grid-Scale Storage

In a bold move that signals the growing importance of long-duration storage, a company founded by former Macquarie bankers has announced plans to build one of Australia’s largest batteries. The facility will boast a massive 4,800 MWh capacity with a six-hour discharge duration, designed to support a wave of new renewable generation projects. Below we answer key questions about this ambitious project.

Who Are the Founders Behind This Battery Project?

The project is being developed by a new venture established by former Macquarie Group bankers. Macquarie has long been a powerhouse in infrastructure and energy finance, and these executives are leveraging their deep industry experience to pivot directly into asset development. The company’s leadership team brings extensive expertise in structuring large-scale energy deals and navigating Australian regulatory environments. While the specific names have not been widely disclosed, the bankers’ track record at Macquarie suggests they can attract significant financing and strategic partners. Their goal is to fill a critical gap in the market: reliable, long-duration storage that can help stabilise the grid as renewable penetration increases.

How Big Is This Battery Compared to Others in Australia?

With 4,800 MWh of storage capacity, this battery ranks among the very largest ever proposed in Australia. For context, the country’s existing big batteries, such as the Victorian Big Battery (450 MWh) and the Hornsdale Power Reserve (150 MWh), are much smaller. Even the planned Waratah Super Battery (1,680 MWh) is dwarfed by this new project. The key differentiator is the six-hour discharge duration; most grid-scale batteries today deliver only one to two hours. This longer duration allows the battery to provide energy during evening peaks, overnight, and through multi-hour renewable lulls, making it a true grid stabilisation asset rather than just a fast-response resource.

Why Is a Six-Hour Battery Important for Australia’s Grid?

Australia’s electricity system is rapidly adding solar and wind generation, which are variable by nature. A six-hour battery addresses a specific need: capturing excess solar power during the middle of the day and discharging it through the late afternoon and evening peak demand period. This helps displace gas-fired peaking plants and reduces reliance on coal, which is increasingly inflexible. Moreover, as coal plants retire, a longer-duration battery can provide the sustained energy needed to maintain supply security. The National Electricity Market (NEM) is moving toward higher renewable shares, and storage with a six-hour horizon is crucial for bridging between sunset and the next day’s solar generation.

How Will This Battery Support New Renewable Generation Projects?

The battery is specifically designed to be co-located or synergistically linked with a swathe of new generation projects. The developers intend to purchase or partner with solar and wind farms to absorb their output when prices are low and inject it back into the grid during high-demand periods. This arrangement provides a stable revenue stream for generators while enhancing the battery’s utilisation. Essentially, the battery acts as a giant time-shifting device, firming variable renewables and making them more valuable. For new renewable projects struggling to secure finance due to price cannibalisation concerns, having a contracted storage partner can be a game-changer.

Where Will the Battery Be Located?

Exact location details have not yet been finalised, but the project is likely to be situated in New South Wales or Victoria, regions with strong renewable development pipelines and high network congestion. These states are also where the most coal plant retirements are scheduled, creating urgent needs for firming capacity. The developers are probably looking for a site with good grid connection capacity, land availability, and proximity to planned renewable energy zones. An announcement on the specific location is expected within the next few months as the project moves into feasibility and permitting stages.

What Is the Timeline for Construction and Operation?

The project is still in early planning stages. The company is currently conducting feasibility studies and seeking environmental approvals. If everything proceeds smoothly, construction could commence in 2025 or 2026, with commercial operation targeted for 2027–2028. This timeline aligns with the anticipated closure of several coal units and the expected growth in renewable generation over the same period. However, given the scale of the battery, supply chain constraints for battery cells and transformers could cause delays. The developers are known for their financial acumen and are likely to place orders early to secure manufacturing capacity.

What Challenges Could the Project Face?

Despite its promise, the battery faces significant hurdles. Capital cost is the primary challenge: a 4,800 MWh facility will require billions of dollars in investment. Securing debt and equity in a high-interest-rate environment may be tough. Grid connection queues in Australia are already congested, with many projects waiting years for approval. Additionally, the company must navigate community opposition if the site is near residential areas or sensitive ecosystems. Finally, competition from alternative technologies like pumped hydro and green hydrogen could shift policy focus. The ex-Macquarie team’s experience in risk management will be critical in steering through these obstacles.