Acciona Energía continues to make progress on the development of the Irene Reversible Hydroelectric Plant, an energy storage project with a capacity of 804 MW located in the Sierra de Alaiz (Navarra), with an estimated investment of close to €900 million. The company has applied for a water concession from the Ebro Hydrographic Confederation to supply the plant with water from the Elorz river, a key step ahead of its commissioning, which is not expected before 2035.
Irene will be Acciona’s first pumped-storage hydroelectric plant in Spain and has been designated a Project of Common Interest (PCI) by the European Union. It will be located in the municipalities of Valle de Elorz and Tiebas-Muruarte de Reta, in the Pamplona area, and will have an installed capacity of 804 MW — expandable to 900 MW — split across three reversible units of 268 MW each, fitted with vertical-axis Francis pump-turbines.
How the plant works
A reversible hydroelectric plant stores energy using two bodies of water at different heights. During periods of low electricity demand, water is pumped from the lower reservoir to the upper one, where it is stored and made available for power generation during periods of higher demand. In Irene’s case, the drop between reservoirs will be 642 metres, with the lower reservoir holding a capacity of 3.75 cubic hectometres.
Procedures under way
The company recently applied for a water concession from the Ebro Hydrographic Confederation, a process that has already secured compatibility with the River Basin Management Plan. The project has also submitted its Environmental Impact Assessment and completed the first phase of geotechnical studies with favourable results. Remaining steps include access and connection to the Muruarte substation, the grid connection permit, the final environmental impact declaration and construction permits.
A strategic project for European energy security
According to Acciona, Irene will provide long-duration storage and high system flexibility, strengthening the stability of the Spanish and European electricity grid and supporting the integration of renewable energy. The project also includes a socioeconomic, environmental and training development programme for the surrounding municipalities, focused on climate commitments, the creation of an agro-ecosystem, improvements for nearby towns and environmental education.
Source: Diario de Navarra