Google and Italian energy storage developer Energy Dome are advancing a 23 MW/200 MWh carbon dioxide battery project in County Offaly, Ireland, aimed at demonstrating how long duration energy storage (LDES) can support renewable heavy grids.
The project represents the first commercial agreement between Google and Energy Dome following their partnership announcement to deploy the company’s CO2 battery technology internationally. Scheduled for commissioning in 2028, the facility has secured a grid connection to the Greater Dublin network and received a 10 year capacity contract from Ireland’s electricity transmission system operator, EirGrid.
Energy Dome will own and operate the project and intends to develop a second 200 MWh installation at the site, creating what the company describes as a domestic LDES hub.
Unlike conventional lithium ion batteries, which are generally optimized for shorter duration applications, Energy Dome’s CO2 battery is designed to store energy over longer periods.
The system uses electricity from the grid to compress carbon dioxide into a liquid state under pressure. When electricity is needed, the stored CO2 is expanded through a turbine, converting the thermal and pressure energy back into electricity.
The approach is intended to address one of the central limitations of renewable power systems: the mismatch between generation and consumption. Solar and wind output can exceed demand during certain periods, while low renewable generation events can create supply gaps.
Long duration storage technologies are increasingly viewed as a complement to short duration batteries because they can shift renewable electricity across longer timeframes. However, the commercial challenge remains proving that these technologies can compete economically with established storage solutions and flexible generation assets.
Ireland provides a relevant market for long duration storage because of its increasing dependence on variable renewable generation.
According to the Sustainable Energy Authority of Ireland, renewable sources accounted for 40.7% of Ireland’s electricity generation in 2023. Renewable deployment also helped avoid approximately 7.4 million tonnes of carbon dioxide emissions during the same year.
The Irish government has set a target of sourcing 80% of electricity from renewable energy by 2030, a level that will require additional grid flexibility.
As renewable penetration increases, system operators face growing challenges related to balancing supply, maintaining frequency stability and ensuring capacity availability during periods of limited renewable output.
The EirGrid capacity agreement provides a commercial mechanism for storage to contribute to reliability, rather than relying only on energy market price differences. This type of contract is becoming increasingly important for emerging storage technologies that require predictable revenue streams to attract investment.
The Google partnership also reflects a wider issue affecting electricity systems: accelerating demand from digital infrastructure.
Data centers require continuous power availability and are increasingly becoming major electricity consumers. Global data center electricity demand is estimated at 460 TWh in 2026, with forecasts from Wood Mackenzie projecting growth to approximately 1,280 TWh by 2030 and 3,700 TWh by 2040.
This expansion is being driven by artificial intelligence workloads, cloud computing growth and increasing digital services demand. For technology companies seeking to reduce operational emissions, renewable power procurement alone may not be sufficient because wind and solar generation do not always align with consumption patterns.
Long duration storage could provide a pathway for companies to match electricity demand with renewable supply over longer periods. However, scaling these technologies will depend on project costs, efficiency improvements and their ability to compete with alternative flexibility solutions.
The Ireland project is part of Energy Dome’s broader commercialization strategy. The company has also announced storage projects with partners including Alliant Energy in the United States, Engie in Italy and NTPC Limited in India.
Google has also been involved in another CO2 battery development with Energy Dome and local utility Salt River Project, targeting a 19 MW/200 MWh project in Arizona.
The increasing interest from utilities and technology companies suggests that LDES is moving beyond demonstration projects toward early commercial deployment. Still, the market remains at an early stage compared with lithium ion storage, which continues to dominate battery installations due to established supply chains and declining costs.
