A rendering of Silver City Energy Centre, a compressed air energy storage plant to be built by Hydrostor in Broken Hill, New South Wales, Australia. Credit: Hydrostor
As the air goes underground, it displaces water from the cavern up a shaft into a reservoir. When it’s time to discharge energy, the system releases water into the cavern, forcing the air to the surface. The air then mixes with the stored heat that the plant stored and this hot, dense air is passed through a turbine to make electricity., Hydrostor says, “Heat is extracted from the air and stored in a proprietary thermal storage tank preserving for use later in the process.
The government of California and the California Energy Commission have made it clear that they want to build long-duration energy storage. The state has estimated that it will need 4 gigawatts of long-term energy storage capacity to be able to meet the goal of 100 percent clean electricity by 2045. Hydrostor and state officials want to see this project get up and running. If that happens, it could provide a showpiece to make the case for building many others.