Energy Dome, SRP and Google Advance Long-Duration Energy Storage Project in Arizona
Energy Dome and Salt River Project (SRP) have announced a new agreement to deploy a 19-megawatt (MW), 10-hour long-duration energy storage (LDES) system to Arizona’s power grid, marking a significant step in expanding next-generation energy infrastructure in the United States.
The project will introduce Energy Dome’s carbon dioxide (CO₂)-based battery technology at the site of SRP’s Coronado Generating Station in St. Johns, Arizona, under a 20-year tolling agreement. Under the arrangement, Energy Dome will own and operate the facility while SRP manages energy dispatch and integration into the grid.
The initiative forms part of the ongoing collaboration between Google and SRP to accelerate deployment of non-lithium-ion energy storage technologies designed to improve grid reliability, affordability, and sustainability.
Once operational, the system is expected to store enough energy to supply approximately 4,275 homes for up to 10 hours, helping strengthen grid resilience amid rising electricity demand.
Claudio Spadacini, Founder and CEO of Energy Dome, said Arizona represents one of the country’s most attractive growth markets as expanding AI infrastructure and increasing energy consumption reshape national energy requirements.
He highlighted that the company’s CO₂ Battery technology provides scalable and dispatchable energy capacity while supporting domestic manufacturing and strengthening long-term energy security.
The technology operates through a thermomechanical storage process, where surplus electricity compresses and stores carbon dioxide. When demand rises, the stored CO₂ is expanded through a turbine to generate electricity and return power to the grid.
The project has also accelerated Energy Dome’s investment in developing U.S.-based supply chains, aligning with broader objectives to support domestic energy infrastructure and create local employment opportunities.
According to Chico Hunter, Manager of Innovation and Development at SRP, the project will allow the utility to evaluate the technology’s real-world performance under Arizona’s climate conditions while diversifying its energy storage portfolio.
Energy storage continues to play an increasingly important role in SRP’s long-term strategy as the utility works toward doubling generating resources by 2035 to meet rising demand across the Phoenix metropolitan area.
Lucia Tian, Director of Advanced Energy Technologies at Google, stated that the company remains committed to accelerating next-generation energy technologies that improve grid resilience and introduce additional clean energy capacity.
She added that the latest project builds on Google’s long-term collaboration with Energy Dome and supports delivery of dependable, cost-effective, and sustainable power solutions for Arizona consumers.
The project is currently scheduled to become operational in 2029, with EPRI, an independent energy research and development institute, supporting performance monitoring and evaluation throughout implementation.
