Energy Dome

Energy Dome was founded in February 2020 in Milan, Italy by Claudio Spadacini (CEO), Dario Rizzi (CTO), and Francesco Oppici (Business Development). The three co-founders had worked together for over 15 years before founding Energy Dome, collectively developing, designing, and building more than 500 MW of geothermal, heat recovery, concentrated solar, biogas, and biomass power plants based on proprietary technologies through their prior ventures. Spadacini, a mechanical engineer who graduated from the Polytechnic University of Milan and holds 45 patents, is a serial entrepreneur who previously founded Exergy S.p.A. (a major developer of geothermal binary cycle ORC turbines) and Sebigas S.p.A. (a global biogas plant developer). The company has offices in Milan, Rome, and Cambridge, Massachusetts.

Energy Dome was founded on a specific thermodynamic insight: CO₂, unlike other gases, has a critical point close to ambient temperature and pressure, which means it transitions between gaseous and liquid states at the conditions relevant to industrial-scale energy storage. This makes it possible to store large quantities of energy in a fully closed loop — using off-peak electricity to liquefy CO₂ and storing it in inexpensive low-pressure tanks, then allowing the CO₂ to re-gasify through ambient temperature and drive a turbine when electricity is needed. The result is a long-duration storage system with high round-trip efficiency, minimal site dependence, no geographic constraints, and a cost structure claimed to be around half that of lithium-ion for multi-hour durations.

Energy Dome has raised over $120 million in total, including an $11 million Series A in 2021 led by 360 Capital and Barclays, a $60 million round in 2022, and a €17.5 million European Commission grant. The company's commercial partners include Engie (Italy) and Alliant Energy (USA), which is deploying a project in Wisconsin. In 2025, Google announced a partnership to support multiple commercial deployments of Energy Dome’s technology — its first publicly disclosed corporate customer for CO₂ storage.

Energy Dome's first commercial CO₂ Battery plant in Sardinia, Italy, has been operating since 2022, making it the world's first operational CO₂ battery at commercial scale. The company has expanded its presence in the United States, with projects targeting the midwest. CEO Spadacini has described the company’s mission as providing the “missing piece” in the renewable energy puzzle: a storage technology that can use the same equipment supply chain as the existing LNG industry, is not dependent on made-in-China components, and is deployable globally without the site constraints of pumped hydro or the mineral supply chain of lithium.