Google & Energy Dome: The 200 MWh CO₂ Battery

Ireland is turning a former fossil-fuel power plant into a giant battery—and it will store energy using carbon dioxide instead of lithium. Google and Italian energy-storage company Energy Dome have signed an agreement to develop a 23 MW/200 MWh CO₂ Battery near Rhode in County Offaly. Expected to begin operating in 2028, the facility could deliver electricity at full power for nearly nine hours. The system operates as a closed loop. When surplus electricity is available, it compresses and liquefies CO₂ inside sealed equipment. When the grid needs power, the CO₂ is heated and expanded through a turbine, generating electricity before being captured and reused again. The gas is not burned or released during normal operation. Unlike conventional lithium-ion batteries, the technology avoids lithium and several other critical battery minerals. Its longer storage duration could help Ireland use more wind and solar power even when the weather changes or electricity demand rises. The project will be constructed at a decommissioned peat-fired power plant, allowing existing industrial land and nearby grid infrastructure to support a new generation of clean-energy technology. It has already secured land, planning approval, a grid connection and a 10-year capacity contract with Irish transmission operator EirGrid. The Irish installation follows a similar 19 MW/200 MWh project announced in Arizona and forms part of Google and Energy Dome’s broader plan to deploy long-duration storage across Europe, North America and the Asia-Pacific region. Energy Dome is led by an experienced executive bench and a team of 100+ engineers, project delivery specialists, and commercial leaders — built to deliver at US utility scale and backed by partnerships with Alliant Energy and Google. Our US headquarters in Cambridge, Massachusetts anchors North American operations, with offices in Milan, Piacenza, Melbourne, Mumbai, and Santiago supporting global project delivery. **Sources & Additional Info**: - [Energy Dome News](https://energydome.com/news/) - [Energy Dome About Us](https://energydome.com/about-us/) - Blathnaid O’Dea, pv magazine Global, July 1, 2026; Google; Energy Dome.