take that with a grain of salt, its still in the "feasibility" and business case phase, there is even articles about the project from 2019 and 2020 and yet not one shovel has been brought out to start the project.
they couldn't even get funding for a 5MW/10MW/h pilot plant
Storage proponent for huge Broken Hill micro-grid fails to land finance for pilot plant | RenewEconomy
Hydrostor energy storage project to contribute to New South Wales economy | Energy Global
Quote:
In 2020, Hydrostor’s 200 MW and 8 hours (or 1600 MWh) A-CAES system was selected by NSW’s Transmission Network Service Provider, Transgrid, as the preferred option in its Regulatory Investment Test for Transmission (RIT-T) for reliable and secure supply for Broken Hill. Hydrostor and Energy Estate are actively developing this project, which has received grant funding from the NSW Government’s Emerging Energy Program to complete pre-feasibility work.