Energy Dome and SRP sign 20-year tolling agreement for 19 MW CO2-based long-duration energy storage project in Arizona

Type: Ppa · Technology: Storage · Country: United States · Capacity: 19 MW · Announced: 2026-06-15

Energy Dome and Salt River Project (SRP) entered a 20-year tolling agreement for a 19 MW, 10-hour carbon dioxide-based (CO2) battery system to be co-located at SRP’s Coronado Generating Station in St. Johns, Arizona. The project, selected through SRP’s 2024 Request for Proposals for long-duration energy storage (LDES) pilots, will store enough energy to power approximately 4,275 homes for 10 hours and is expected to come online in 2029. Google will fund a portion of the project through a cost-sharing agreement with SRP as part of their broader collaboration to accelerate non-lithium-ion LDES technologies. The system utilizes Energy Dome’s proprietary CO2 Battery technology, which compresses and stores CO2 using grid power and expands it through a turbine to generate energy when needed. SRP and Energy Dome will collaborate with EPRI to monitor performance data from the project.

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