Australia’s energy transition took a major step forward on January 7, 2026, as Origin Energy announced the commercial commencement of the first stage of the Eraring Battery Energy Storage System (BESS). Located on the western shore of Lake Macquarie in New South Wales’ Hunter region, the project is reshaping the future of a site that remains the largest operational coal-fired power station in the country.
While the Eraring Power Station continues to supply approximately one-quarter of the state's electricity, its role is evolving. Under an agreement with the NSW Government, the coal plant’s retirement has been scheduled for August 2027 to ensure grid reliability while the state transitions to renewable energy. The new battery system, built near Morisset and Dora Creek, is designed to eventually replace the firming capacity provided by coal.
A Critical Asset for Grid Stability
Large-scale batteries have become central to Australia’s energy security. The Eraring battery provides stability to the National Electricity Market (NEM) by "soaking up" excess solar and wind energy during the day and releasing it back into the grid during periods of peak demand.
The site offers a significant strategic advantage: high-capacity transmission infrastructure is already in place. By utilizing the existing connection points of the power station, the project reduces the need for costly new power lines and minimizes further environmental impacts on the local area.
Scale and Specifications
The Eraring battery is being delivered in four stages. With the recent final investment decision on Stage 4, the project’s total capacity will reach 700 megawatts (MW) and 3,160 megawatt-hours (MWh) once fully complete. This makes it the largest battery development by energy capacity (MWh) in the Southern Hemisphere, though it is surpassed in power output by the 850 MW Waratah Super Battery also located in NSW.
- Stages 1 and 3: Now combined into a single operational unit, providing 460 MW of power and 1,770 MWh of storage. This phase officially entered commercial operations in early January 2026.
- Stages 2 and 4: Currently under construction, these stages will add another 240 MW of capacity. Stage 4 specifically extends the dispatch duration of this phase to approximately 5.8 hours, allowing for deeper support during long evening peaks. These stages are expected to come online in the first quarter of 2027.
Construction and Partnerships
Progress across the 17-hectare site—equivalent to 24 soccer fields—has been steady. Bulk civil works are complete, and ongoing activity focuses on the electrical fit-out of over 2,000 battery enclosures and 180 kilometers of cabling. To maintain the project's momentum, approval was granted for extended construction hours through May 2026.
Origin’s Executive General Manager of Energy Supply and Operations, Greg Jarvis, noted that the project is the result of extensive collaboration with partners including Wärtsilä, Enerven, Jacobs, Lumea, and Transgrid. Jarvis emphasized that the battery's ability to "firm" renewable energy strengthens the reliability of the entire system.
As the coal-fired station approaches its final years of operation, the battery development signals a new chapter for Eraring. Rather than closing the doors on energy production, the site is being repositioned as a cornerstone of Australia’s renewable transition, ensuring the lights stay on across New South Wales for decades to come.
Data and project specifications sourced from Origin Energy’s Eraring Project updates: Eraring BESS
