Neoen, a French renewable energy and storage developer, has secured a new contract to expand the Collie battery with more Tesla Megapacks. The expansion will see the project become Australia’s largest battery energy storage system (BESS), continuing the country’s shift towards renewable energy resources and away from traditional coal power.
The project will see the addition of a 341 MW, 1,363 MWh second stage to the Collie BESS, boosting its total capacity to 560 MW and 2,240 MWh. The first stage of the battery, currently under construction, already features 219 MW and 877 MWh. Both stages utilize Tesla Megapack technology and are being constructed by UGL.
This expansion not only overshadows the nearby Synergy’s 500 MW, 2,000 MWh battery, which is still under construction, but also sets a new benchmark in the region by supporting 20% of the average demand in Western Australia’s South West Interconnected System (SWIS).
This is particularly noteworthy as SWIS operates as an isolated grid, with no connections to other states or countries, mimicking energy transition dynamics seen in places like California where batteries significantly contribute to evening peak energy supply.
The BESS is located in Collie, a town historically dominated by coal power. However, the battery’s expansion is timely as the state’s coal generators expected to shut down within five years.
The awarded contract requires the battery to soak up solar power for a period of four hours and discharge that capacity for four hours across the evening peak. This is part of a broader initiative, Non-Co-optimised Essential System Services (NCESS), which aims to facilitate a smoother transition from coal to renewables across the state.
The contract, which also includes other projects like Synergy’s Kwinana battery and Alinta’s Wagerup facility, is scheduled to start in October 2025.
