Pumped storage back in focus

Ireland’s long-awaited expansion of pumped hydro storage is moving closer to the planning stage, with the proposed Silvermines Hydro project in County Tipperary progressing through its European Project of Common Interest (PCI) consenting process.

The project aims repurpose the former Silvermines mining site to provide up to 296MW of generation capacity and just under 2.2GWh of daily electricity storage. The existing mine pit would form the lower reservoir, with a new upper reservoir constructed higher on Silvermines Mountain.

If successful, the project would allow electricity to be used to pump water uphill when renewable generation exceeds demand, with the stored water subsequently released through turbines to generate electricity when required.

In February 2026, Minister for Climate, Energy and the Environment Darragh O’Brien TD said long-duration storage projects such as pumped hydro could play a “critical role” in providing flexibility and security of supply, while facilitating the integration of renewable generation and shifting electricity to periods when it is most needed.

Silvermines has held PCI status under the EU’s Trans-European Networks for Energy regulations since the fourth PCI list and was due to remain on the forthcoming list. The designation provides access to EU funding and is intended to facilitate the development of strategically important energy infrastructure. In 2023, Silvermines received €4.3 million from the Connecting Europe Facility for environmental and design studies.

The project is now in the pre-application phase of the PCI permit-granting process. An Coimisiún Pleanála, acting as Ireland’s national competent authority for PCI projects, deemed it sufficiently mature to enter the pre-application phase in February 2025.

The developer has said geological surveys, habitat assessments, water studies, environmental reviews, and engineering design are ongoing.

If successful, Silvermines would be only the second pumped storage facility in the State. ESB’s Turlough Hill station in County Wicklow, operational since 1974, has 292MW of generation capacity and approximately 1.6GWh of storage.

According to figures released by EirGrid 13.2 per cent of wind generation and 11.2 per cent of total renewable generation was dispatched down in the first half of 2026, representing electricity that could not be accommodated on the system at the time.

EirGrid’s 2026-2035 capacity assessment identifies pumped storage alongside batteries and other technologies as part of Ireland’s future storage mix. Silvermines would add substantial long-duration capacity to a system increasingly reliant on variable renewable generation, although construction remains subject to the completion of the statutory consenting process.