The state’s energy minister, Penny Sharpe, stated that once constructed and connected, the initiative would “prevent a recurrence” of a recent emergency situation the Far West area of New South Wales faced after severe storms on 17 October caused disruptions to electricity supplies in Broken Hill and nearby communities.
A Crown Lands agreement is a lease granting the occupant exclusive permission to utilize and inhabit state-owned land for a specified purpose and duration under the NSW Crown Land Administration Act 2016.
The lease established with the Crown Lands office at the Department of Planning, Housing, and Infrastructure (DPHI) permits Hydrostor to utilize the site in Broken Hill for 65 years.
The long-duration energy storage (LDES) resource will integrate into the National Electricity Market (NEM), while an agreement has already been enacted with transmission system operator (TSO) Transgrid in 2022 for 250MWh of its capacity.
Transgrid selected the initiative through a competitive process to find a preferred option to support the city’s power supply. Broken Hill is a historical mining region, and Hydrostor CEO Curtis VanWalleghem remarked in an Energy-Storage.news interview that its baseload and peak capacity is primarily provided at present by outdated diesel generators.
Asserted efficiency and environmental advancements
Hydrostor possesses the intellectual property for the proprietary A-CAES technology. VanWalleghem asserted that while conventional CAES projects function reliably, their limitations include a dependence on natural gas to heat air prior to its expansion as the systems release energy.
A-CAES employs a thermal management system that closes the loop of heating and cooling. Heat generated during compression is harnessed rather than expelled and is subsequently stored in hot water, which is utilized to pre-warm the air before its expansion.
Another claimed innovation is that while CAES typically utilized salt caverns for compressed air storage, Hydrostor’s design allows the air to be stored in hard rock caverns. These caverns are often employed in the mining and hydrocarbon sectors, and thus existing mine sites, such as the Potosi mine at Silver City in NSW, can be repurposed.
Just over a year ago, the Canadian technology firm signed a binding agreement with mining company Perilya for utilizing existing mine assets and infrastructure at Potosi.
State aiming for 28GWh long-duration storage by 2034
In mid-October, severe storm conditions damaged seven of Transgrid’s transmission towers in Broken Hill and the Far West region of NSW, significantly interrupting the power supply in the city and its neighboring areas.
Backup generators activated, but planned and unexpected outages occurred to help keep it operational, while a new 50MW/100MWh battery energy storage system (BESS) in Broken Hill owned by AGL was called into action by Transgrid.
“Recent events in the Far West region of NSW have highlighted the necessity for long-duration storage to secure energy supply for Broken Hill and the Far West,” NSW energy minister Penny Sharpe stated at the time of the deal with Hydrostor.
“This initiative will replace the older large-scale backup diesel generators, preventing a recurrence of the recent energy emergency in the Far West region of NSW,” Sharpe remarked, adding that the Silver City A-CAES system would “position Broken Hill as a leader in renewable energy,” incorporating more clean energy into the state’s energy mix and aiding in reducing electricity costs.
In addition to some financial support from the NSW Emerging Energy Opportunities Program, Hydrostor’s initiative has also received backing at the federal level, from the Australian Renewable Energy Agency (ARENA). ARENA committed AU$49 million (US$29 million) towards the projected total cost of AU$652 million in 2022.
Silver City has also received a Long Term Energy Service Agreement (LTESA) contract under a NSW state policy roadmap, awarded to Hydrostor by AEMO Services in late 2023.
CEO VanWalleghem characterized the agreement to provide firming capability to the grid as “a significant vote of confidence in not only long-duration energy storage but also our compressed air solution as a crucial technology pathway for decarbonization and grid reliability across Australia.”
New South Wales energy minister Sharpe recently revealed plans to legislate a 28GWh long-duration energy storage target for the state by 2034. Its current objective is for 2GW of 8-hour duration storage (16GWh) by 2030, under the NSW Electricity Infrastructure Roadmap 20-year plan.
The first contract for LDES under a government biannual tender process as outlined in the Roadmap was awarded in 2023 to RWE for a 50MW/400MWh lithium-ion (Li-ion) BESS project.
RWE has since made the Final Investment Decision (FID) to advance that project into construction, while the state government has granted Critical State Vital Infrastructure status to three long-duration pumped hydro energy storage (PHES) projects in development.
