Hydrostor has received grid connection approval for its “near-shovel ready” Silver City Energy Storage Centre project being developed in Broken Hill, New South Wales. The project, the first of its kind in Australia, features a 200 MW underground compressed air energy storage (CAES) facility that will deliver 1,600 MWh, or at least eight hours, of energy storage for Broken Hill and surrounding areas.

The Silver City project has now passed a critical regulatory requirement with Hydrostor announcing it has received grid connection approval from the Australian Energy Market Operator (AEMO) and state transmission company Transgrid.

Hydrostor Country Lead Martin Becker said the approval confirms the Silver City project meets Generator Performance Standards and is a major milestone in securing all the necessary regulatory approvals to connect to the NSW transmission network.

“Grid connection approval is another significant step for Silver City and reflects the considerable work that has gone into progressing a critical piece of energy infrastructure for Broken Hill,” he said, noting the project has undergone a rigorous assessment process involving extensive modeling, simulations and network studies.

The Silver City project will use Hydrostor’s CAES technology that produces heated compressed air using excess electricity during periods of low energy demand. The compressed air is sent down a shaft into an underground cavern. When energy is required, compressed air is sent back up the shaft to drive a turbine, which generates electricity.

Company president Jon Norman told pv magazine in May that the company’s CAES system can achieve around 60% to 65% round-trip efficiency.

Hydrostor said once completed, Silver City will operate as a large-scale energy storage asset connected to the New South Wales grid, storing energy when it is abundant and dispatching it when needed.

“When fully charged, the project will have enough storage capacity to supply the equivalent of more than 80,000 homes for a day,” the company said in a statement. “The project will support renewable energy generation, improve grid reliability and provide a long-term energy security solution for Broken Hill and the wider region.”

The project will provide up to eight hours of long-duration energy storage, with 50 MW/250 MWh reserved to provide backup power for Broken Hill and the state’s far west during network outages.

Becker said long-duration energy storage will be essential as Australia brings more renewable generation online, providing reliable power when it is needed and strengthening the resilience of the grid.

“While delivering a project as innovative and complex as Silver City presents challenges, the long-term benefits for Broken Hill and the Far West, including greater energy security, new investment, jobs and economic activity, make it a project worth getting right,” he said.

The Silver City Energy Storage Centre is Hydrostor’s first project in Australia, and builds on its operational 2 MW demonstration project in Canada. The company said it has a 7 GW project pipeline of CAES projects globally, including another “near-shovel-ready” 500 MW project in California.

Hydrostor is also seeking to develop a 500 MW project in the Cultana/Whyalla region of South Australia and is advancing two 500 MW early-stage development opportunities in western and southwest Victoria.