A massive 200 MWh storage facility in Ireland. Energy Dome will turn a former peat‑fired power plant into the green heart of the grid

Italian startup Energy Dome, in cooperation with tech giant Google, will carry out an interesting investment in Ireland’s long‑duration energy storage sector. A large‑scale storage facility with a power rating of 23 MW and a record capacity of 200 MWh will be built in County Offaly, based on the company’s proprietary technology that uses carbon dioxide. The project already has all necessary permits and secured financing through a capacity market contract.

How does a carbon battery work?

The greatest advantage of the technology developed by Energy Dome is complete independence from lithium, cobalt or nickel — raw materials burdened with geopolitical risks, supply chain vulnerabilities and rapid cell degradation. Instead, the system uses a closed loop of carbon dioxide, manipulating its physical state:

Charging – when the grid has an excess of cheap renewable energy, the system draws electricity and compresses gaseous carbon dioxide at high pressure (approx. 70 bar), turning it into a liquid. The heat generated during this process is captured and stored in a dedicated thermal system. Liquid CO₂ can be safely stored in steel tanks at ambient temperature for any length of time.

Discharging – when the grid demands electricity, the previously stored heat is transferred back to the liquid CO₂. The liquid rapidly evaporates and expands into hot, high‑pressure gas. The accelerated gas drives a turbine connected to a generator, producing electricity and feeding it into the grid. The expanded gas returns to a large, flexible dome, completing a closed process in which no gases are emitted into the atmosphere.

The efficiency of this cycle exceeds 75%, and the installation’s lifespan is estimated at a minimum of 30 years without capacity loss.

Strategic location on former industrial grounds

The investment will be built in County Offaly, in close proximity to the Rhode Green Energy Park — a region characterized by a high concentration of onshore wind and solar farms. The location is not accidental:

• The CO₂ battery will be constructed on the grounds of a former peat‑fired power plant. This is an excellent example of a just energy transition, where old fossil‑fuel infrastructure is repurposed for zero‑emission technologies.
• The facility will be located near high‑voltage transmission lines supplying the Dublin metropolitan area, which is Europe’s hub for data centers — including cloud and AI infrastructure owned by Google.

The project is scheduled to become operational in 2028. It already has secured land, planning permissions, grid connection terms, and a 10‑year capacity contract awarded by Ireland’s transmission system operator EirGrid. The owner and operator of the facility will be Energy Dome, which is already planning to add a second, twin unit with a capacity of 200 MWh at the same site.

Global alliance with Google for 24/7 clean energy

The Irish contract is another step in the strategic partnership between Google and Energy Dome, officially launched in July 2025. The corporation’s goal is clear — to provide its data centers with round‑the‑clock, zero‑emission power.

Just a month earlier, in June, both companies announced a twin project to build a carbon battery with parameters of 19 MW / 200 MWh in Arizona, also located on the grounds of a former conventional power plant. As Claudio Spadacini, CEO of Energy Dome, emphasizes, the project in Ireland will pave the way for further commercial deployments of long‑duration energy storage technology in Europe, North America, and the Asia‑Pacific region.