STOR-HY: More flexible, efficient and resilient hydropower storage for the European electricity grid

The acceleration of variable renewable energies, such as wind and photovoltaic energy, requires the storage capacity and flexibility of the European electricity grid to be strengthened. In this context, pumped-storage hydropower plants are key infrastructures for storing energy at large scale, responding rapidly to demand peaks and providing ancillary services that improve the stability of the electricity system. In the EU, it is estimated that more than 95% of energy stored at electricity-grid level is stored using this technology.

However, the new role of these plants in an energy system with a larger renewable component involves more demanding operating conditions: more frequent starts and stops, rapid changes in operating mode, operation across wider ranges and greater exposure of critical components to degradation phenomena. All this may increase operation and maintenance costs, reduce plant availability and create risks of unplanned outages.

STOR-HY (for its name, Innovative storage technology and operations in hydropower) responds to this challenge with an approach aimed at minimising the CAPEX (Capital Expenditure or initial investment) and OPEX (Operational Expenditure) of innovative hydropower storage projects. To achieve this, the project works to extend the service life of components and equipment in pumped-storage hydropower plants, improve their recyclability and define operating strategies adapted to non-conventional schemes, such as installations in complex environments or under particularly demanding conditions.

The solution combines advanced sensor-based monitoring systems, digital operational management tools, real-time controllers, high-level computational models and predictive maintenance algorithms. These systems make it possible to detect failure mechanisms at early stages, anticipate degradation processes and avoid both unnecessary maintenance interventions and unexpected shutdowns. In this way, plants can operate with greater reliability, availability and efficiency.

One of the central elements of the project is the cyber-physical platform for advanced decision support, called CADS —Cyber-physical platform for Advanced Decision Support—. This platform integrates monitoring data, computational models and operational information to realistically estimate the degradation of critical components, both in short-term operations and in long-term operating scenarios. The information generated supports decision-making in plant operation and facilitates the design of innovative control strategies for highly complex conditions.

The proposed solution is being validated in six European demonstrators located in France, Portugal and the United Kingdom: Vouglans–Saut Mortier–Coiselet, Le Cheylas and La Rance in France; Alqueva and Vilarinho das Furnas in Portugal; and an innovative small-scale dense-fluid demonstrator. These cases cover different innovative or demanding situations, such as tandem pumping, tidal power plants using salt water, hybrid battery and floating photovoltaic plants, and the reuse of a former coal mine for hydropower storage.

The contribution of the CDIF at UPC, an expert centre in hydropower turbomachinery vibrations, industrial diagnosis, preventive maintenance and damage detection, focuses on the diagnosis, modelling and advanced monitoring of hydraulic systems and critical components, as well as on fluid-dynamic and mechanical simulations (CFD and finite elements). The centre contributes to the development of methodologies capable of linking real operational data with computational models to better understand equipment behaviour, estimate its health status and support more informed operational decisions. This experience is particularly relevant for expanding the operating range of pumped-storage plants and increasing the flexibility of hydropower generation and storage in Europe.

In addition to its technological impact, STOR-HY incorporates a sustainability perspective covering environmental, circularity, economic and social aspects. The project considers issues such as local impacts, social acceptance, ecological considerations and life-cycle cost analysis. It also prioritises the creation of regional connections with local stakeholders, industry, academia and public institutions, with the aim of fostering the transfer of results and their application in the energy sector.

Consortium, Budget and Funding

STOR-HY is funded by the European Union under the Horizon Europe programme (GA No. 101172905). It has a duration of 48 months (October 2024 - September 2028) and a total budget of 9.58 million euros.

The consortium is made up of 18 partners from 8 countries. In addition to UPC, the partners are: GE Vernova, EDP Centre for New Energy Technologies, EDP Produção, Électricité de France, INESC TEC, Universiteit Twente, vgbe, Zabala Innovation, Norwegian Research Centre, KAIZEN Solutions, Institut polytechnique de Grenoble, Sener, Hulleras del Norte, Sociedad Asturiana de Diversificación Minera, Fundación Asturiana de la Energía, Haute école spécialisée de Suisse occidentale and ANDRITZ.