Google has announced a strategic partnership with Italian firm Energy Dome to deploy innovative carbon dioxide (CO2)-based long-duration energy storage (LDES) systems across its global renewable energy projects. This collaboration marks a significant step towards enabling continuous, carbon-free energy operations, addressing the inherent intermittency of solar and wind power.

The initiative focuses on integrating Energy Dome's proprietary CO2 Battery technology, which has already demonstrated commercial viability. Unlike conventional lithium-ion batteries that typically offer only up to four hours of backup power, Energy Dome's system is designed to provide clean, dispatchable energy for up to 24 hours. This extended duration is critical for bridging gaps during prolonged periods of low renewable generation, such as overnight or during extended cloudy and windless conditions.

The CO2 Battery operates on a unique thermodynamic cycle. It stores electricity by compressing carbon dioxide gas into a liquid. When the grid requires power, the liquid CO2 is heated and expanded back into a gas, which then spins a turbine to generate electricity. Once the gas cools, it is recaptured in a closed-loop system within a large dome for future use. This process utilizes off-the-shelf mechanical components and fundamental physics, avoiding reliance on expensive or difficult-to-source materials often associated with other battery chemistries.

Energy Dome has successfully proven the technology at its first commercial facility in Sardinia, Italy. This plant, boasting a capacity of 20 megawatts (MW) and 200 megawatt-hours (MWh), has been operating effectively for over three years, validating the CO2 Battery's performance and reliability in a real-world grid environment. Google's backing is expected to significantly accelerate the global rollout of this technology, with planned commercial deployments in key regions including North America, Europe, and the Asia-Pacific.

This investment aligns directly with Google's ambitious goal of operating on 24/7 carbon-free energy by 2030. Beyond supporting Google's data centers, the scalability and inherent inertia provided by the CO2 Battery's spinning machinery will contribute to broader grid stability. As more fossil fuel plants retire, these LDES systems can help maintain consistent power flow and frequency, which is vital for a resilient and modern electricity infrastructure. The partnership underscores a growing industry recognition that long-duration storage is indispensable for a truly decarbonized and reliable energy future.