Innovative Grid Scale Renewable Energy Storage


Pumped hydroelectric power stations have very long operating lives; typically well in excess of 50 years.  They are well proven with over 100,000MW of installed capacity around the world.

The plans for Silvermines Hydro comprise:

  • Remediation works to the lower reservoir incorporating the existing artificial lake at the site;
  • The turbine hall connecting to the lower reservoir that contains the pump/turbines and auxiliary plant;
  • An intake/outlet structure and steel penstock connecting the upper reservoir to the power plant;
  • An intake/outfall structure connecting the power plant to the lower reservoir;
  • An upper reservoir constructed in a valley below the mountain ridge at the site
  • Transformers and switchgear to connect the plant to the transmission grid;
  • An underground cable connection to the grid.

The underground powerhouse (turbine hall) will contain three 120MW pump/turbine units.  This configuration provides a balance between the flexibility and reliability of multiple small units and the economies of scale of large units.

The average difference in elevation between the upper and lower reservoirs is approximately 300m.  Each reservoir will have a water capacity capable of providing up to six hours of energy storage.

Grid Connection

The project is located at a geographical grid strong point, within 5km of two major transmission lines.  The transmission lines are the 400kV Moneypoint to Dunstown and the 220kV Killonan to Shannonbridge.

The selected location for the Project eliminates the need for extensive new network build, while also offering improved network resilience and grid reinforcement positives.

Silvermines Hydro will connect into the existing national transmission network, with electricity flowing to or from the wider transmission and distribution networks, providing power to customers where it is needed.  The proposed physical connection to the grid will comprise an underground cable route connecting to the existing 400kV and 220kV transmission lines.

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Planning Process

Given the strategic nature of the planned investment, it is likely Silvermines Hydro shall be considered ‘strategic infrastructure’, in accordance with the Strategic Infrastructure Development, Planning and Development Act 2006.

Project design activities, studies and environmental assessments are currently being carried out.  Consultations are also on-going with all key stakeholders for input into the development process.

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Project Feasibility Report

After an extensive site selection process, the project site at Silvermines was identified as best equipped to accommodate Ireland’s second pumped hydroelectric power station.

The Project Feasibility Report concluded that, based on the assessments and design undertaken during the feasibility stage, the proposed hydroelectric power station at Silvermines is considered a viable project, technically and economically.

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Active Supporters Group

We are very interested to hear from you and are currently collecting names for our Active Supporters Group. If you support the project and would like to join the group please contact us at For any other query please visit our contact page.

Joining our Active Supporters Group is a simple and powerful way to express your support for the Project. We really appreciate any support, comments or ideas. We look forward to keeping the Silvermines Active Supporters Group up to date on all aspects of the Project.