The first demonstrator project of its carbon dioxide-based energy storage solution has been launched by Italian startup Energy Dome. The CO₂ battery can store renewable energy over long periods and release it quickly at less than half the cost of large lithium batteries.

The 4 MWh system in Sardinia, Italy, features a maximum output of 2.5 MW and uses huge domes with giant, flexible bladders full of CO₂ gas, which is condensed into a liquid at ambient temperature. Heat created by the compression process is stored in thermal energy storage systems, and when energy needs to be released, the CO₂ is evaporated and expanded into a turbine. The gas then returns to the dome, serving as an atmospheric gasholder, ready for the next charging cycle.

[See also: CO₂ battery demonstration planned in Italy]

The first CO2 battery facility is now fully operational. Source: Energy Dome

By relying on storage in the liquid phase at ambient temperature, typical storage costs associated with compressed air energy storage are reduced without having to maintain the cryogenic temperatures associated with liquid air energy storage.

A full-scale 20 MW/200 MWh commercial plant is scheduled to be deployed by the end of 2023.