A new long-duration energy storage project using CO2 battery technology is being developed in Ireland to supply Google and provide grid support services. The project, led by Energy Dome, was reported on 26 June 2026 and marks a notable step in Ireland's effort to back up its rapidly growing solar capacity with storage that can hold energy for extended periods.
What is a CO2 battery?
Energy Dome's technology stores energy by compressing CO2 into a liquid state and releasing it through a turbine when power is needed. Unlike lithium-ion batteries, which are optimised for short-duration discharge, CO2 batteries are designed for long-duration storage — holding energy across many hours rather than a few. This makes them better suited to smoothing out the variability that comes with a grid increasingly dependent on solar and wind generation.
Why does this matter for an installer working in Ireland right now?
On the surface, a grid-scale storage deal with a hyperscale data centre looks a long way from a residential or commercial rooftop installation. But the connection is direct.
Ireland's solar capacity has expanded dramatically in recent years. That growth has exposed a structural problem: the grid was not built to absorb power from thousands of distributed sources at once. Grid connection delays, curtailment, and export limits are already real constraints for installers trying to get projects approved and commissioned. Long-duration storage at grid level helps by absorbing excess generation during peak production periods and releasing it when demand rises — reducing the pressure on network operators to restrict exports from smaller installations.
“Grid-scale storage doesn't replace rooftop solar — it makes more of it viable by giving the network somewhere to put the surplus.”
The corporate power purchase angle
The fact that this project is tied to a corporate offtake agreement with Google is also worth noting. Large technology companies operating data centres in Ireland have become significant drivers of energy infrastructure investment. When those companies commit to long-duration storage projects, it accelerates the commercial case for the technology and brings down costs over time — eventually benefiting smaller storage products in the residential market too.
What installers should watch
- Grid connection timelines: more storage capacity on the network should, over time, ease the curtailment pressure that is currently delaying some solar farm connections and affecting export tariff stability.
- Residential battery pricing: as long-duration storage technology matures at grid scale, costs for behind-the-meter storage products tend to follow downward.
- Customer conversations: homeowners are increasingly aware of grid constraints and export payment issues. Being able to explain how grid-scale storage fits into the wider picture builds trust and positions you as a knowledgeable installer rather than just a fitter.
- Future grid services: EirGrid has been clear that dispatchable, flexible resources — including storage — will be needed to meet Ireland's renewable targets. That policy direction supports ongoing investment in grid infrastructure.
The bigger picture
Ireland's solar buildout has moved faster than its grid and regulatory frameworks. Storage projects like Energy Dome's CO2 battery help close that gap at the infrastructure level. They will not fix every connection delay tomorrow, but they are part of the investment cycle that makes a high-solar grid workable in the long run.
For installers, the practical upshot is straightforward: the case for solar in Ireland keeps strengthening, and staying on top of grant paperwork remains one of the most controllable variables in your business. Every project that moves quickly through the SEAI application process is a project that gets commissioned before the next policy update or grid constraint bites. Keeping your documentation clean and complete is still the fastest route from signed contract to paid installation.