Finnish marine and energy technology group Wärtsilä was contracted to supply the BESS solution in a deal booked in Q4 2024 and announced in February 2025, covering engineering design, supply, commissioning and a 15-year service agreement.
The system uses Wärtsilä’s Quantum High Energy hardware and the company’s GEMS Digital Energy Platform and is designed to operate in grid-forming mode, enabling it to provide synthetic inertia and faster response times to stabilise the grid as coal-fired generation retires from the Victorian system.
When Wärtsilä launched the Quantum High Energy product in late 2023, the company said it delivered 9% greater energy density than the previous generation through the use of 306Ah lithium-ion cells, alongside fire safety improvements including active dehumidification, prefabricated fire walls between units and a dual sprinkler system.
That higher energy density directly reduces the number of units required per site and, by extension, the footprint and logistics complexity of delivering a project at Wooreen’s scale, where 1,038 individual units have now been received, staged, and installed.
In July 2025, EnergyAustralia sold a 50% share in the 1,400MWh Wooreen BESS to Thailand-based energy firm Banpu Public Company. The deal cost in the region of AU$700 million (US$490 million), with Banpu to provide an equity injection of AU$110 million.
