Collie to be home to Australia’s biggest battery

An expansion to a battery in Collie to store midday solar power collected on the state’s biggest power grid for use in the evening will make it Australia’s largest energy storage site.

The expansion is to serve a two-year storage contract from October 2025 that French firm Neoen won after a competitive tender run by the Australian Energy Market Operator that controls the power grid in south-west WA.

Kate Ryan, AEMO manager for WA, welcomed the investment.

“Neoen’s Collie Battery will play an important role as we navigate through WA’s energy transition, supporting the state’s future energy needs as coal-fired generation retires,” she said.

The WA government’s 2023 budget allocated $2.8 billion for energy storage, wind generation and upgrades to the transmission system.

Supplying power to the state’s populous south-west is getting increasingly complex as demand rises, continuing installation of rooftop solar panels causes a difficult-to-manage midday power supply peak, and slow progress is made in building new wind farms.

Substantial amounts of additional renewable and gas generation are needed before state-owned power generator Synergy closes its last two coal-fired power plants in 2027 and 2029.

Neoen is building stage one of its Collie battery after winning a similar contract in mid-2023. It is planned to start operating by December 2024 and will be able to charge or discharge 200 megawatts over four hours.

The French firm also operates Australia’s original grid-scale battery at Hornsdale in South Australia and the Victorian Big Battery.