Engie has signed an ‘energy storage as a service’ contract with technology provider Energy Dome for a long-duration energy storage (LDES) project in Sardinia, Italy.
The French multinational utility and the Italian startup announced the commercial offtake agreement for Energy Dome’s 20MW/200MWh CO2 Battery this morning.
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The 10-hour duration project in the Sardinian municipality of Ottana is currently under construction and is the first large-scale system using Energy Dome’s technology. It follows a couple of years of operation of a 2.5MW/4MWh commercial CO2 Battery demonstrator, also in Sardinia.
The project is due to be completed by the end of the first quarter of 2025. It has received funding through a partnership between European Union (EU) entities, including the European Investment Bank (EIB) and the Catalyst programme for supporting sustainability technologies run by Bill Gates’s Breakthrough Energy venture capital (VC) group. The programme invested €60 million (US$65.37 million) into the project last December.
The CO2 Battery, designed by Energy Dome’s CEO, inventor, and entrepreneur Claudio Spadacini, stores energy through adiabatic compression of carbon dioxide gas, which is liquified during charging and evaporates during discharge in a thermodynamic cycle.
The startup has claimed the technology is simple and safe, built using a combination of off-the-shelf components and techniques taken from existing industries, using abundant and easy-to-source raw materials.
Energy Dome intends to also build projects which it will sell on to customers to own, but the Engie deal falls under the storage as a service business model the Italian startup has also been marketing.
Energy Dome will continue to own and operate the asset, although Engie will optimise its dispatch into Italy’s power markets.
The company is also developing an identically designed project in Wisconsin, US, and signed a contract with utility Alliant Energy in October. The US project is scheduled to begin construction in 2026 and start commercial operation in 2027.
Energy Dome was the winner in the LDES Company of the Year category at the 2024 Energy Storage Awards, which were hosted by Solar Media, our publisher.
Engie meanwhile noted that the CO2 Battery resource will be added to its portfolio of energy storage resources in Italy that so far comprises 43MW/48MWh of lithium-ion (Li-ion) battery energy storage systems (BESS).
“The European Investment Bank plays a key role in accelerating the green transition by financing breakthrough technologies like Energy Dome’s CO2 Battery,” EIB vice president Gelsomina Vigliotti said.
“This partnership is a tangible example of a replicable commercial innovation and confirms the Ottana CO2 Battery is not just a demonstration but a viable facility, which will unlock Nth-of-a-kind opportunities that can lead to true global scale,” head of Breakthrough Energy’s Catalyst accelerator Mario Fernandez said.
Financial terms of the deal were not disclosed.
