Western Australia Urged to Expand Long-Duration Battery Storage Amid Energy Transition

As Western Australia moves toward phasing out coal-fired power, a new report highlights the critical need for large-scale deployment of long-duration battery energy storage systems (BESS) alongside significant wind and solar expansion.

According to the Australian Energy Market Operator (AEMO), ensuring the reliability and stability of the South West Interconnected System (SWIS) will require substantial investment in six-hour energy storage solutions. This recommendation comes as the region prepares for changing electricity demand patterns, new power generation, and planned retirements of aging infrastructure.

AEMO’s 2025 Electricity Statement of Opportunities, released this month, notes that SWIS is one of the most geographically isolated major power systems in the world. This unique characteristic makes it especially vulnerable to shifts in energy technology, generation sources, weather extremes, and user behavior.

Over the past two years, extreme heatwaves have triggered unprecedented spikes in electricity demand due to increased cooling requirements, pushing the system to record peak loads. To address this growing challenge, over 1,000MW of new battery storage capacity is expected to come online between now and 2026-27. This storage will help smooth rapid fluctuations in electricity usage and absorb excess solar generation during daylight hours, reducing the risk of emergency curtailments of batteries and solar facilities.

Despite this progress, AEMO forecasts a small 50MW shortfall in capacity for the 2025-26 summer—though this is less severe than deficits projected in recent years. Meanwhile, nearly 2,000MW of aging coal and gas plants are set to be retired between 2027 and 2032, reinforcing the urgency of further investment in clean energy storage.

Nicola Falcon, AEMO’s interim executive general manager for Western Australia, noted that nearly 500MW of battery storage has already entered operation in the SWIS since 2023. An additional 728MW of committed projects are scheduled to be online by 2025-26.

“Strong investment in battery infrastructure in recent years has helped reduce previously anticipated risks to system reliability,” Falcon said, emphasizing the vital role energy storage will play in Western Australia’s transition to a more sustainable power grid.