In the world of renewable energy, where the reliability of sources like wind and solar power remains a challenge, the pursuit of efficient and cost-effective energy storage solutions is relentless. While lithium-ion batteries have dominated this landscape, a promising contender has emerged, driven by an unexpected ally – carbon dioxide.
Enter the CO2 battery, an imaginative concept materialized by the innovative minds at Energy Dome, an Italian startup. The mechanism is ingeniously simple: carbon dioxide is stored in a colossal dome. During the charging phase, the system extracts the gas, compresses it into a liquid, and stores it in substantial carbon steel tanks. Notably, the compression process generates heat, which is preserved in steel shot and quartzite “bricks” for future use.
When power demand arises, the liquid carbon dioxide undergoes rapid heating using the stored thermal energy, transforming it back into a gas that refills the dome. During this return journey, the gas spins a turbine, generating electricity to meet the energy needs.
Energy Dome’s first pilot plant, nestled near Ottana on the picturesque island of Sardinia, Italy, showcases the practical application of this revolutionary technology. The closed-loop system efficiently utilizes a minimal amount of CO2, requiring only a single injection into the dome throughout the battery’s 30-year lifespan. This sustainable approach aligns with the broader goal of supporting the widespread adoption of renewable energies, ultimately contributing to reduced carbon emissions.
Compared to traditional compressed air and liquid air energy storage technologies, the CO2 battery offers distinct advantages. The density of pure carbon dioxide surpasses that of air, enabling energy storage in a significantly smaller space – up to ten times smaller than compressed air. Unlike liquid air energy storage, which demands extreme cooling, the CO2 battery operates at ambient temperatures, enhancing efficiency and affordability.
Built from steel, carbon dioxide, and water, the CO2 batteries boast a minimalist design, with additional components like pipes, compressors, and turbines readily available off the shelf. According to Energy Dome, this simplicity translates into a substantial cost advantage, allowing their system to produce electricity at half the cost of lithium-ion batteries.
The remarkable potential of CO2 batteries has attracted substantial investment. At COP28, Bill Gates’ Breakthrough Energy Ventures and the European Investment Bank committed €60mn to support Energy Dome’s construction of its first commercial-scale plant in Sardinia. This adds to the €80mn in funding already secured by the startup.
The upcoming plant in Sardinia, set to store 20MW of renewable energy from nearby solar and wind farms, marks a pivotal step in the technology’s development. Gelsomina Vigliotti, vice president at the EIB, hails the initiative as a “game-changing technology” needed on a broader scale.
Energy Dome’s founder, Claudio Spadacini, envisions the Sardinia plant as the prototype for many identical full-scale CO2 batteries. The modular and straightforward design of the CO2 battery facilitates rapid scalability. A partnership with Norwegian wind energy giant Ørsted signals further expansion, with plans for the installation of CO2 batteries at multiple European sites beginning as early as 2024.
While lithium-ion batteries continue to play a crucial role in the energy transition, concerns about their environmental and social impact have propelled alternative technologies into the spotlight. If CO2 batteries can navigate these challenges and undercut lithium-ion on cost, they may emerge as the next frontier in energy storage, reshaping the future of sustainable power.