Australia Achieves Battery Storage Milestone with First 8-Hour System
RWE has received official sign-off from the Australian Energy Market Operator (AEMO) and Transmission Network Service Provider Transgrid to operate Australia’s first eight hour Battery Energy Storage System (BESS) at full capacity. The Limondale BESS comprises 144 Tesla Megapacks that are uniquely registered to charge at 100 megawatts (MW) and discharge at 50 megawatts (MW).
The achievement, announced on May 27, represents a significant breakthrough for Australia’s energy storage capabilities. The BESS will be able to deliver its registered maximum discharge output for more than eight hours. This corresponds to a storage capacity of at least 400 megawatt hours (MWh), making it the longest-duration battery currently operating in Australia.
Located adjacent to the RWE Limondale Solar Farm near Balranald in southern New South Wales, the battery helps reduce network pressures during peak demand, supporting a more flexible and secure electricity system.
Breaking New Ground in Long-Duration Storage
The Limondale project defied industry expectations that batteries would remain limited to shorter storage periods. The project, which was sized at 8 hours in response to the New South Wales Government’s Electricity Infrastructure Roadmap, was the first to receive a Long Duration Storage (LDS) Long-Term Energy Service Agreement (LTESA) as part of the first tender undertaken by ASL (an AEMO subsidiary). This award underscored early investment in LDS projects, highlighting the project’s important role in supporting the state’s energy transition and integrating renewable energy sources.
“This groundbreaking project transforms battery storage in Australia, marking a significant milestone in the development of long-duration energy storage and enhancing the reliability and resilience of the national energy system.” - Sopna Sury, CEO, RWE Renewables Europe & Australia
Following commissioning of the Limondale BESS, the battery has successfully undergone grid compliance and performance tests, demonstrating the plant’s ability to safely operate at maximum capacity.
Technical Specifications and Market Impact
The system’s unique charging and discharging specifications set it apart from conventional battery installations. While most grid-scale batteries operate at equal charge and discharge rates, the Limondale system can charge at twice the rate it discharges, allowing it to capture excess solar generation during peak production hours more efficiently.
| Specification | Detail |
|---|---|
| Capacity | 50MW / 400MWh |
| Duration | 8+ hours |
| Technology | 144 Tesla Megapacks |
| Charging Rate | 100MW |
| Discharging Rate | 50MW |
| Location | Balranald, NSW South-West REZ |
The Limondale BESS connects to the grid via Limondale Solar Farm’s existing 33 kV substation, reducing need for new infrastructure. The co-location with RWE’s existing 314MW solar farm, which generates enough electricity to power 105,000 homes annually, creates an integrated renewable energy hub.
Pipeline of Long-Duration Projects
Although RWE’s Limondale BESS is the first 8-hour BESS in Australia to gain full operational approval, other long-duration storage batteries are being developed nationwide. Australian developer Edify Energy, acquired by global investment group La Caisse (formerly CDPQ), received federal approval in September 2025 for a 2,400MWh 8-hour BESS in Victoria. The Nowingi hybrid project will pair a 300MW solar PV plant with an integrated 300MW/2,400MWh BESS.
The success of lithium-ion technology for long-duration storage has attracted global attention. Many LDES lithium-ion battery storage projects are now advancing and attracting global market interest, driven by falling system costs, higher power densities, and modularity.
Supporting Australia’s Renewable Transition
The 8-hour duration capability positions the Limondale BESS to address longer periods of supply-demand imbalance than shorter-duration systems. The 8-hour duration capability positions the Limondale BESS to address longer periods of supply-demand imbalance than shorter-duration systems, which typically focus on frequency control and peak shaving applications. This extended duration enables the system to provide backup during periods of low renewable energy generation or high demand, potentially reducing reliance on gas peaker plants.
For Australian households considering battery storage, the project demonstrates the ongoing evolution of grid-scale storage technology. While home systems typically offer 2-4 hours of backup power, projects like Limondale show how large-scale storage can complement residential installations by providing grid stability and reducing wholesale electricity costs.
Your 2026 Guide: Precisely Sizing a Home Battery for Your Solar System & Usage can help homeowners determine the right capacity for their needs, while Unlock $1,000+ Annually: Best Home Battery VPP Programs in Australia 2026 Ranked explores how residential batteries can participate in grid services similar to utility-scale projects.
RWE currently operates battery storage systems with a total capacity of 1.7 gigawatts (GW), with a further approximately 2.5 GW under construction. As an integral part of its growth strategy, RWE plans to significantly expand its battery storage capacities worldwide.
The Limondale BESS approval marks a turning point for Australia’s energy storage sector, proving that lithium-ion technology can deliver the extended duration capabilities previously thought to require alternative technologies like pumped hydro or thermal storage. As the nation continues its renewable energy transition, long-duration battery storage systems like Limondale will play an increasingly critical role in ensuring grid stability and energy security.