June 2026 – STOR-HY

STOR-HY in their words: INESC TEC

Posted on 25/06/202610/07/2026 by STOR-HY

INESC TEC is a private, non-profit research association with public interest status, committed to scientific research and technological development, operating at the intersection of academia, industry, public administration, and society. The research centre connects these sectors by applying its research findings to technology transfer projects, focusing on generating value and delivering societal impact.

INESC TEC comprises 13 R&D centres, including the Centre of Power and Energy Systems, which is involved in the STOR-HY project to bring expertise in power systems, energy storage modelling, and electricity and ancillary service markets, focusing on hybridisation of pumped-storage hydropower plants (PSPs) with photovoltaic (PV) and battery energy storage systems (BESS) and optimisation of market participation.

Contribution to STOR-HY

INESC TEC’s main contributions to STOR-HY unfold in two directions: assessing the flexibility contribution of the various innovative technological solutions in STOR-HY to the power system and optimising the Alqueva triple-hybrid demonstrator in ancillary services markets.

The first of these contributions is framed within the STOR-HY matrix. Building on the flexibility matrix presented in the XFLEX Hydro project (2019-2023), the new matrix provides an updated view of the flexibility dimension in the current European ancillary services landscape, considering new pan-European market mechanisms and requirements for service provision. Through dynamic simulations, INESC TEC is evaluating the demonstrators’ ability to provide various ancillary services while complying with these requirements. Additionally, the new STOR-HY matrix incorporates environmental and societal dimensions developed by the partners at the University of Twente and NORCE, respectively.

The second contribution focuses on optimising the operation of a hybrid hydropower-floating PV-BESS plant in the electricity and frequency regulation markets. INESC TEC is developing a rolling-horizon model predictive control layer that continuously re-optimises setpoints in order to absorb intraday deviations while honouring day-ahead and ancillary service commitments.

The Alqueva hydropower plant, a 520 MW facility and the first triple hybrid system in the EU, serves as the demonstrator for this framework combining hydropower, photovoltaics, and battery storage, making it an ideal testbed for integrated market-operation strategies.

Coordinating market participation and plant control at Alqueva

At INESC TEC, we are developing operational tools within STOR-HY that connect market decisions with hydropower plant control. Our framework has two decision layers: one for market participation and the other for real-time operations.

The first layer focuses on the day-ahead market and ancillary services. Optimisation models are used to schedule generation and ancillary service bids for the following day, taking into account respecting reservoir and operational constraints.
The second layer operates closer to real time. Built on model predictive control, it continuously updates the plant’s operating setpoints as the day unfolds. Because renewable generation can differ from forecasts, the plant often has to adjust its operations during the day while remaining within its market commitments.

Flexibility is only valuable if it can be delivered reliably. By linking market scheduling with real-time control, the framework enables plants such as Alqueva to provide flexibility services while making better use of available water resources.

Challenges and opportunities of hydropower in the EU

Modern hydropower plants do not operate in isolation: they are cornerstones of electricity markets, making up most of the global storage capacity and can rapidly adapt to the ever-changing energy landscape. Thanks to the general time-dispatchability of their power generation, they can offer a wide range of operational flexibility.

Furthermore, traditional fixed-speed hydropower plants and PSPs contribute to the power system inertia by their very nature. However, they have some limitations. For instance, they have a slow response time to frequency variations or power setpoints, and their range for reactive power provision and absorption is limited. Moreover, operating these plants in frequency control can induce behaviours in the machines that accelerate wear and tear on the mechanical components, such as frequent setpoint adjustments or mode changes from pump to turbine. Given the wide variety of ancillary services that a PSP can provide and their respective market frameworks, optimally balancing the operation of the plant across different markets to increase revenues is a complex, multifaceted task.

Conclusion

STOR-HY aims to address the many challenges of PSP in an evolving power system, where renewable and converter-interfaced generation are on the rise. Hydropower has the capacity and responsibility to respond to these new challenges and the potential to contribute more to power system stability and generate new sources of revenue. These factors drive research and technological innovation projects such as STOR-HY.

Taking these steps is paramount in moving towards power systems that rely less on fossil fuels and more on renewable energy. This has long been a priority for the European Union and is a pillar of INESC TEC’s commitment to society.

Fourth consortium meeting and review meeting

Posted on 05/06/202610/07/2026 by STOR-HY

On 3–4 June 2026, the STOR-HY consortium convened in Brussels for its fourth consortium meeting and first review meeting, bringing together project partners, the Project Officer from the Climate, Infrastructure and Environment Executive Agency (CINEA), an external reviewer, and one of the Chairs of the International Advisory Board. This two-day event offered the chance to evaluate progress made during the initial reporting period, discuss ongoing activities and define priorities for the next phase of the project.

Reviewing progress across the project

The meeting opened with a presentation by project coordinator Alexandre Presas Batlló (Universitat Politècnica de Catalunya), who provided an overview of the project’s achievements to date. At month 18, STOR-HY remains on track to deliver innovative pumped storage hydropower solutions, having submitted 16 deliverables, published several scientific publications, and developed a growing portfolio of communication and stakeholder engagement activities.

Partners then presented progress across all work packages.

WP2 reported advances in defining the technical, economic, environmental, regulatory, and social requirements for future pumped storage plants through the development of the STOR-HY matrix, which was presented in a workshop last July. Significant progress has also been made in defining business use cases for all demonstrators and developing methodologies to assess social acceptance and environmental performance.

WP3 showcased developments in advanced monitoring technologies and the Cyber-physical platform for Advanced Decision Support (CADS). Monitoring systems are already operational at several demonstrators, while work continues on virtual sensors, predictive maintenance strategies, CFD and FEM models, and the cloud-based CADS platform that will support operational decision-making.

WP4 presented progress on innovative control and operational management strategies for pumped storage plants. These activities included developing advanced control algorithms, optimisation tools for energy management and ancillary services, battery sizing methodologies, and concepts for hybridising hydropower with batteries and photovoltaic systems.

WP5 highlighted advances in technologies for harsh operating environments and saltwater applications. Partners reported progress on their work with anti-corrosion coatings, biofouling mitigation solutions, sediment monitoring technologies, and studies exploring the future potential of saltwater pumped storage hydropower in Europe.

Demonstrating innovation in real operating environments

A key focus of the meeting was WP6 and the project’s demonstrators, which are essential for validating STOR-HY technologies under real operating conditions. Updates on the demonstrators at Vouglans–Saut Mortier–Coiselet, Le Cheylas, La Rance, Alqueva, and Vilarinho das Furnas were presented. The activities presented ranged from advanced monitoring campaigns and wear-and-tear assessments to biofouling mitigation, hybridisation studies, and innovative operational strategies for increasing flexibility.

Sustainability, exploitation, stakeholder engagement, communication and dissemination

Progress was also reported on the project’s sustainability activities. WP7 presented initial results of the life-cycle assessment, biodiversity analysis, circular economy evaluation, life-cycle costing, and social acceptance studies. These activities will contribute to a comprehensive sustainability framework capable of evaluating the environmental, economic, and social impact of innovative hydropower solutions.

WP8 presented ongoing work to maximise the long-term impact of STOR-HY through exploitation planning, market analysis, and the identification of Key Exploitable Results (KERs). The first version of the project’s Exploitation Master Plan is currently being prepared to support the future uptake of STOR-HY technologies.

WP9 presented the progress achieved in stakeholder engagement, communication, dissemination, and training activities. During the first reporting period, the project launched its website and social media channels, published scientific papers and technical articles, organised public events and workshops, and strengthened collaboration with other European hydropower initiatives.

A successful first review

The second day of the meeting was dedicated to the review of the first reporting period. The consortium presented its achievements to the Project Officer and the external reviewer, who assessed the project’s progress against its objectives and planned activities.

The review was successful, and the consortium received positive feedback on the quality of the work performed. The reviewers recognised the project’s achievements and provided valuable recommendations for the next stages of implementation.

Having established a solid foundation established during its first 18 months, STOR-HY now enters the next phase of the project with a clear roadmap for advancing innovative technologies and operational solutions that will contribute to the future of pumped storage hydropower in Europe.

We would like to thank all the partners for their contributions, the International Advisory Board for its continued support, and the Project Officer and reviewer for their constructive feedback and guidance throughout the review process.

STOR-HY in their words: EDF

Posted on 01/06/202610/07/2026 by STOR-HY

EDF is a French multinational energy company, primarily owned by the French state. It operates nuclear, hydro, wind, solar, and thermal power plants. EDF supplies electricity and energy services across Europe and worldwide to millions of customers. EDF participates in the STOR‑HY project through two entities: EDF Hydro and EDF R&D. EDF R&D is the research and innovation division of the EDF Group. It develops advanced technologies supporting low‑carbon electricity generation, nuclear safety, renewable energies, power grids, and digital solutions.

EDF Hydro is a major player in hydropower in France. With an installed capacity exceeding 20 GW, hydropower represents approximately 15% of EDF’s national electricity production. The hydro fleet includes more than 400 power plants and 600 dams, operated by around 5,000 employees. EDF Hydro operates six pumped‑storage power plants (PSPP), representing a total of 5 GW of installed capacity. Each year, EDF Hydro invests over €500 million in maintenance and modernisation, ensuring the long‑term safety, reliability, and performance of its assets.

Within STOR‑HY, EDF specifically addresses key challenges related to hydropower‑based energy storage, carrying out tests and measurements at several power plants in close collaboration with the industrial and academic partners of the consortium.

Vouglans – Saut‑Mortier – Coiselet (VSMC)

Vouglans, Saut‑Mortier, and Coiselet form a cascade of three dams and associated power plants located in the Jura Mountains, with a combined installed capacity of approximately 370 MW. Ongoing works to add pumping capability at Saut‑Mortier will make this site a representative example of cascaded pumped‑storage operation.

Challenges: Managing increased mechanical wear due to intensified operation, exploring potential evolutions of the Unit 4 pump start‑up mode at Vouglans, and limiting the environmental impact of flushing operations on biodiversity.
Research: Studies focused on optimizing cascade operation and improving Unit 4 pump start‑up strategies.
Testing: Site tests are planned for 2027, including strain‑gauge measurements on Unit 4, supported by hydraulic scale‑model testing and theoretical modeling. This site also contributes to research on low‑head tandem pumping.

Le Cheylas

Le Cheylas is a pumped‑storage power plant located in the Alps, commissioned in 1980, and equipped with two 230 MW units. The plant operates under a head of approximately 260 m.

Challenges: Adapting operation to the 15‑minute electricity market (ArchyFlex) to reduce start-stop cycles, and anticipating the impact of sediment transport on machine wear.
Control systems: The validation of upgraded control commands was completed in 2025, enabling new transitions from turbine mode to synchronous compensator mode.
Testing: Additional instrumentation was installed in August 2025. A dedicated test campaign is planned for September 2026 to evaluate solutions aimed at enhancing the flexibility and extending the lifetime of this 45‑year‑old PSPP.

La Rance

La Rance is a unique tidal power station, commissioned in 1966, and remains a global reference in marine renewable energy. It is equipped with 24 reversible generating units, each rated at 10 MW, for a total installed capacity of 240 MW.

Focus: Saltwater tidal pumped‑storage‑like operation.
Challenges: Mitigating biofouling effects and assessing the integration of a battery system to better align tidal‑constrained operation with market requirements.
Testing: Biofouling tests are ongoing, with test coupons installed in May 2024. Cleaning trials were conducted in November 2025, evaluating techniques such as sponge cleaning, cavitation jets, and underwater brushing.

Conclusion

EDF’s active involvement in the STOR‑HY project demonstrates its strong commitment to advancing innovative and sustainable energy storage solutions. By leveraging its extensive hydropower expertise, conducting large‑scale experimental campaigns on real facilities, and closely collaborating with industrial and academic partners, EDF plays a key role in bridging research and operational deployment. These efforts reinforce EDF’s position as a major driver of the energy transition, supporting more resilient, flexible, and low‑carbon power systems for the future.