Australian grid operator backs grid-forming battery technology to bolster system strength

New South Wales (NSW) transmission network operator Transgrid plans to add more grid-forming batteries to its portfolio to provide essential system strength services to the state’s electricity grid as ageing coal-fired generators continue to exit the transmission network.

Transgrid, as the system strength service provider for NSW, had previously called for the contracting of up to 5 GW of grid-forming batteries, along with 10 synchronous condensors, to replicate the critical system services traditionally provided by coal, gas and hydro, but the grid operator said it has now reassessed its plan.

In the revised portfolio, Transgrid reconfirms the need for synchronous condensers but reduces the number from 10 units to eight and allows for an expanded role for grid-forming batteries.

Transgrid Executive General Manager of Network Jason Krstanoski said the shift in technologies is in response to “rapidly changing market conditions,” including the rising cost and delayed availability of synchronous condensers, and updates to anticipated NSW coal retirement timelines.

“The power system is becoming more complex at a faster rate, with shifting demand patterns, evolving technologies and multiple possible future pathways,” he said.

“In this environment, maintaining flexibility in how system strength is delivered is critical to ensuring the lowest cost outcome for consumers.”

Transgrid’s initial plan relied heavily on batteries, but only for a grid-stabilising role to enable new solar and wind generators to connect and operate securely, known as the ‘efficient’ level of system strength.

The network operator said it is now looking at utilizing grid-forming batteries to also help meet the ‘minimum’ level of system strength needed to keep the power system safe and secure with the delays to coal retirement dates providing additional time to prove the capabilities of the technology.

“We’re creating a pathway for grid‑forming batteries to form part of the minimum-level portfolio in a measured way, with their role subject to confirmation of their technical credibility, which we hope to see in the coming years,” Krstanoski said.

“This includes confirming that battery systems can reliably provide the required characteristics and performance of system strength needed for the safe operation of protection systems, before we rely upon them to deliver it in practice.”

Transgrid’s update calls for 900 MW of grid-forming batteries, ideally located in the Sydney West region, by the early 2030s to provide ‘minimum’ level system strength. This would be in addition to the 5 GW of capacity that was identified in the initial portfolio.

The network operator has already shortlisted nine battery projects with a combined capacity of 2 GW to address system strength needs as they emerge.

Krstanoski said the updated portfolio also includes fallback options such as hydro and gas support, ensuring minimum system strength levels can still be delivered if battery capability is delayed or under-delivers.

“By combining proven infrastructure with emerging technologies, we are maintaining system security while increasing flexibility and reducing costs for consumers,” he said.