Discover
Safe, Reliable, and Clean Long Duration Energy Storage for California

Willow Rock is a 500 MW Advanced Compressed Air Energy Storage (A-CAES) facility that is under late-stage development in California. California requires large-scale, long duration energy storage to fully integrate increasing levels of renewable generation capacity and to serve expected load growth, which Willow Rock is positioned to serve.

About the project

As California modernizes its grid infrastructure A-CAES will provide reliable energy security for more than 50+ years.

The Willow Rock Energy Storage Centre will create over 700 construction jobs, bring over $500 million in direct and indirect benefits to the local economy, and leverage proven technology that is built and operated by skilled jobs similar to the regions established oil and gas industry, providing stable, long-term employment opportunities.

The proposed Center will discharge 4,000 megawatt hours (MWh) of electricity, capable of delivering 8+ hours of energy delivery on a full charge.

Project highlights

Willow Rock Energy Storage Center from above
Size
500 MW / 4,000 megawatt hours (MWh)
Owner
Hydrostor
Location
Kern County, California
Application
Renewables Integration, Transmission Optimization
Economic
25-40 full-time equivalent jobs during operation, an estimated peak workforce of 700 jobs during construction, and over $500 million of regional direct and indirect economic impacts.
Project Design Life
50+ years

Benefits

Community
Electricity Grid
Environment
Driving economic growth

With a 50+ year lifetime, the facility will provide a stable revenue source for local communities. A-CAES plants use standard components and provides stable, well-paying jobs for workers from the fossil-fuel industry.

The project will support diversified wage job opportunities and generate significant regional economic development from both the construction and operation of the project.

Electricity grid benefits

Willow Rock will allow California’s growing solar and wind resources to be directly converted into reliable, on-demand electricity for the greater Los Angeles region and the broader California grid for decades in the future.

Enabling firm capacity

The project supports the delivery of dispatchable electrical capacity into the Los Angeles Basin and broader California grid, and ensures sufficient long duration energy storage resources are available well into the future as they becomes increasingly important to reliably serve load.

Delivering transmission system value

Optimize the use of the existing transmission system, by storing excess energy during times of abundance and dispatching this energy when it is most needed, allowing for more efficient use of transmission lines to deliver reliable service and ensure new transmission is built where it is most needed.

Technological diversification

Offers technology diversity for the California grid to help enable grid resilience and provide different generation characteristics when compared to the other grid assets and storage technologies.

Supports statewide targets

Willow Rock will help California reliably meet electricity demand, and is key to enabling SB100 and LA100 objectives for 100% carbon-free renewable electricity by 2045.

Minimal land and water requirements

A-CAES offers the equivalent bulk energy storage capabilities as pumped hydro storage with substantially lower land and water requirements. A-CAES is a sustainable energy storage technology that is non-combustible, has minimal residual hazardous waste at asset retirement and will experience virtually no performance degradation over its commercial lifetime.

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Stimulate economic growth and new jobs

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Improve grid reliability and help prevent future blackouts

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Deploy proven technologies and existing workforce skills

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Vendor Registration

We want to know more about the local businesses that operate in or around Kern County, CA. If you’re interested in lending your services to the project, visit our vendor interest form.

Proud to be a part of the East Kern
County Community

Hydrostor is proud to have been part of the East Kern County community for more than five years
since announcing the Willow Rock Energy Storage Center.



Committed to being a good neighbor and a good partner in the region


We’re supporting local communities like Mojave, California City, and Rosamond—areas that have historically faced underinvestment. In recognition that there is no one-size-fits-all approach to serving Kern’s diverse communities, collaboration with various community and business-led organizations has opened numerous opportunities to identify and address specific needs.

We’re proud to support non-profit groups that are making a real impact


We look for organizations promoting education, economic development, and community well-being. Our partners include:

  • Safe Haven Kids League
  • The Kern Economic Development Foundation
  • The Antelope Valley College Foundation

We value our partnerships with local community and business groups


As we advance the Willow Rock Energy Storage Center, we’re excited to grow our partnerships. These include:

  • Area chambers of commerce
  • Mojave Air and Space Port
  • Edwards Air Force Base.

Other projects


Goderich Energy Storage Centre


The Goderich Energy Storage Centre, located in Goderich, Ontario, is the world’s first commercially contracted Advanced Compressed Air Energy Storage facility.

Demonstrating the viability of A-CAES technology, the plant is contracted by Ontario’s Independent Electricity System Operator (IESO) for peaking capacity, ancillary services, and full participation in the merchant energy market to support grid reliability.

Silver City Energy Storage Centre


Silver City is a 200 MW Advanced Compressed Air Energy Storage facility under advanced development in Broken Hill, NSW, that provides unmatched benefits to consumers in a remote region with extensive renewable infrastructure and resources.

Get in touch

Get in touch

    Toronto office

    333 Bay Street, Suite 520
    Toronto Ontario M5H2R2
    Canada
    (416) 548-7880

    Denver office

    1125 17th Street, Suite 700
    Denver, Colorado 80202 USA

    Melbourne office

    Suite 8.02, Level 8, 420 St.Kilda Road
    Melbourne, Victoria 3004
    Australia