Hydrostor’s Willow Rock Energy Storage Center Obtains Final Approval for Power Plant License

Audio By Carbonatix

DENVER--(BUSINESS WIRE)--Dec 19, 2025--

Hydrostor, a leading global long duration energy storage (LDES) developer and operator, is pleased to announce that the Willow Rock Energy Storage Center received final permitting approval from the California Energy Commission (CEC), positioning the project to be shovel-ready in 2026. The 500 MW / 4,000 MWh advanced compressed air energy storage (A-CAES) project can store energy for eight hours of continuous discharge to the grid, and will provide reliability and resiliency amidst rapidly rising electricity demand.

“This permit from the CEC is a crucial milestone to realizing the benefits of the Willow Rock project, and helps to unlock the rest of our multi-gigawatt pipeline in North America. We’re appreciative of all the work that has gone into reaching this important milestone,” said Curtis VanWalleghem, Hydrostor Co-Founder and CEO. “Our A-CAES technology will be key to reliably meeting expected demand increases driven in part by data centers and AI, while also maintaining affordability for existing customers. We’re excited to show the world the benefits A-CAES can bring to the grid.”

Jon Norman, Hydrostor President, said, “We’re grateful to the Commissioners, CEC staff, and all of our community stakeholders for the work that went into permitting the Willow Rock Energy Storage Center, which will be a critical economic driver for Kern County and the surrounding region. Now, we’re eager to get to work bringing the project to life, creating thousands of jobs and enhancing energy reliability and resiliency.”

Strategically located in Kern County, Hydrostor’s innovative storage technology stores surplus energy, which it is then able to discharge during peak use hours. The project will be able to power more than 400,000 homes for more than eight hours and will bring more than $500M in investment to the East Kern County and the greater Antelope Valley, in addition to thousands of jobs during construction and 40 full-time jobs for its 50-year operational lifetime.

The project received its franchise agreement from the Kern County Board of Supervisors as of early December, and received a conditional letter of support also from the Kern County Board of Supervisors in April.

The Willow Rock Energy Storage Center is Hydrostor’s first utility-scale project being built in the U.S. The company is developing another late-stage project in New South Wales, Australia, and has a 7 GW project pipeline globally, with projects in the U.S., Australia, Canada, and the UK.

About Hydrostor Inc.

Hydrostor is a leading developer and operator of long duration energy storage systems, leveraging a proven, patented technology solution for delivering long duration energy storage to power grids around the world, using compressed air and water to store energy.

Founded in 2010 and with headquarters in Toronto, Canada and offices in Melbourne, Australia, and Denver, USA, Hydrostor is backed by Goldman Sachs Alternatives, CPP Investments, Canada Growth Fund, and other forward-thinking institutional investors, providing financial security to commit to top-tier energy projects. Hydrostor has an extensive pipeline of A-CAES projects in North America, Australia, and Europe, poised to meet their evolving grid and reliability needs.

Follow us on LinkedIn.

To learn more, visit https://www.hydrostor.ca/.

View source version on businesswire.com:https://www.businesswire.com/news/home/20251219659175/en/

CONTACT: Emily Smith

703-888-7025

[email protected]

KEYWORD: COLORADO UNITED STATES NORTH AMERICA

INDUSTRY KEYWORD: OTHER ENERGY ENVIRONMENT UTILITIES SUSTAINABILITY ALTERNATIVE ENERGY ENERGY

SOURCE: Hydrostor

Copyright Business Wire 2025.

PUB: 12/19/2025 03:48 PM/DISC: 12/19/2025 03:49 PM

http://www.businesswire.com/news/home/20251219659175/en