Arizona utility Salt River Project signed an agreement with Energy Dome to install a 19-MW, 10-hour carbon dioxide battery system at the Coronado Generating Station. The project will be built at the site of a coal plant that is transitioning to natural gas, making it a real-world test of long-duration storage paired with fossil fuel infrastructure retirement. The CO2 battery technology uses compressed carbon dioxide in a closed-loop cycle to store and discharge electricity over longer periods than typical lithium-ion systems. If this pilot performs well, it could offer a model for other utilities looking to repurpose coal plant sites for grid-scale storage while maintaining reliability during the transition.
