Energy Dome Uses CO2 Batteries for 24-Hour Energy Storage

Energy Dome has developed a novel energy storage solution utilizing compressed carbon dioxide gas, designed to provide power for up to 24 hours and address the intermittency of renewable energy sources. As solar and onshore wind power become increasingly prevalent due to their low cost and rapid deployment, their inherent variability necessitates robust storage mechanisms to ensure a stable energy supply. Energy Dome's technology aims to bridge the gaps between energy supply and demand by storing and releasing energy through a cycle involving compressed carbon dioxide.

The core of an Energy Dome plant is a substantial dome structure, approximately the size of seven soccer fields, which houses around 2,000 metric tons of carbon dioxide. The process begins when surplus energy, such as that generated by a connected solar farm, is used to power compressors. These compressors liquefy the carbon dioxide by increasing its pressure, and this liquid is then stored in specialized carbon-steel tanks. A crucial aspect of this compression process is the generation of heat, which Energy Dome captures and stores in a proprietary thermal storage material. This stored heat is essential for the subsequent energy release phase.

When the electricity grid requires power, the stored liquid carbon dioxide is released from the tanks. The system then utilizes the captured heat to warm the carbon dioxide, converting it back into a gaseous state. This high-pressure gaseous carbon dioxide is directed through a turbine, which generates electricity. Following its passage through the turbine, the gas returns to the dome, completing the cycle and preparing for the next storage operation. This closed-loop system allows for continuous energy storage and retrieval.

While the concept of storing energy using compressed gas is not new, with utilities having long employed compressed air in underground caverns, Energy Dome's approach offers a significant advantage: it does not require specific geological formations to function. This flexibility in deployment means that Energy Dome's technology can be more readily scaled and implemented across diverse geographical locations worldwide, facilitating broader adoption for grid stabilization. The company activated its inaugural commercial plant in Sardinia, Italy, in 2025. This facility boasts a storage capacity of 200 megawatt-hours, sufficient to power approximately 18,000 Italian homes for a duration of 10 hours. Energy Dome has ambitious expansion plans, with a stated intention to develop 30 gigawatt-hours of projects across five continents, underscoring its potential impact on the global energy storage landscape.