Long-duration energy storage (LDES) developer-operator Hydrostor has announced a strategic technology and equity agreement with energy infrastructure equipment manufacturer Baker Hughes.
The agreement will enable Hydrostor to incorporate Baker Hughes’ technology into its main design for its advanced compressed air energy storage (A-CAES) solution. This includes orders for up to 1.4GW of Baker Hughes equipment for Hydrostor’s flagship projects, including compression, expander, motor, and generator technology.
A-CAES technology operates by compressing and directing air into a storage medium to load the system. When discharging, the system releases the stored air through a heating process that causes expansion, powering a turbine generator.
Similar to traditional CAES, A-CAES captures heat from the compressor and transfers it through heat exchangers to store in pressurized water. This water is kept in a reservoir and released into a cavern to displace air during discharge, a process known as hydrostatic compensation.
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Hydrostor ranked fifth overall on a new leaderboard of long-duration energy storage companies from research and consultancy firm Sightline Climate, which ranks suppliers by technology, finance, deployment and economics.
As reported by ESN Premium today, lithium-ion battery energy storage system (BESS) providers Tesla and Chint Power topped the Sightline Climate LDES Leaderboard. Sightline research associate Lukas Karapin-Springorum spoke exclusively with the site today about the rankings, which also include other LDES names familiar to Energy-Storage.news readers, such as ‘CO2 Battery’ provider Energy Dome and liquid air energy storage (LAES) tech company Highview Power.
Recently, the company received final permitting approval from the California Energy Commission (CEC) for the 500MW/4,000MWh A-CAES Willow Rock Energy Storage Centre.
Hydrostor initially signed a 200MW/1,600MWh power purchase agreement (PPA) for Willow Rock in 2022 with California’s Central Coast Community Energy (3CE).
At that time, the company mentioned it was negotiating several offtake deals for the remaining capacity at Willow Rock.
In September 2025, the company obtained US$55 million in funding from Export Development Canada (EDC) to support development activities for its 200MW/1,600MWh A-CAES Silver City Energy Storage Centre project in Broken Hill, New South Wales, Australia.
The Silver City Energy Storage Centre will deliver eight hours of storage duration at full output capacity. It aims to replace aging diesel generators nearing the end of their lifespan and will also provide essential grid stability services to the overall network.
Hydrostor’s CEO, Curtis VanWalleghem, stated that the EDC funding boosts the Silver City project and highlights growing global backing for LDES, especially for A-CAES technology.
Baker Hughes has been an investor in Hydrostor since 2019. The company says this latest agreement marks an expansion of its relationship as Hydrostor nears construction of its two flagship projects.
The Energy Storage Summit USA will be held from 24-25 March 2026, in Dallas, TX. It features keynote speeches and panel discussions on topics like FEOC challenges, power demand forecasting, and managing the BESS supply chain. For complete information, visit the Energy Storage Summit USA website.
The Energy Storage Summit Australia 2026 will be returning to Sydney on 18-19 March. It features keynote speeches and panel discussions on topics such as the Capacity Investment Scheme, long-duration energy storage, and BESS revenue streams. ESN Premium subscribers receive an exclusive discount on ticket prices. To secure your tickets and learn more about the event, please visit the official website.
