At the International Forum on Pumped Storage Hydropower, one of the most anticipated sessions, “Innovating for Grid Flexibility: New Technology Showcase”, highlighted how pumped storage hydropower (PSH) is evolving to meet the demands of renewable-dominated power systems.

The session was co-moderated by Prof. em. Dr. Anton Schleiss, Coordinator of ETIP HYDROPOWER, together with Matteo Bianciotto, Policy and Research Director at the International Hydropower Association (IHA), which is also a partner of ETIP HYDROPOWER. Their moderation reflected ETIP HYDROPOWER’s active role in guiding Europe’s hydropower innovation agenda.

Innovation at the heart of PSH

The debate demonstrated that although PSH is a mature and proven technology, it is constantly adapting to address new challenges. Experts exchanged views on variable speed technology, battery–turbine hybridisation, hydraulic short circuit solutions, plant digitalisation, and design and construction challenges.

Case studies and perspectives

The panel brought together a wide range of international expertise:

• Alexander Speckle, Member of the Board of Directors at TIWAG
• Parveen Nanda, Executive Vice President at Greenko
• Elena Vagnoni, Head of Projects Group, PTMH, EPFL
• Romain Pellegrino, Chief Commercial and Strategy Officer, Hydropower, GE Vernova
• Danilo Moresco, Global Business Line Manager, ABB

Opening the session, Alexander Speckle presented the Kühtai 2 Pumped Storage Plant in Austria, which expands an existing facility to cover winter electricity shortages. He explained how the project integrates variable speed machines and a new reservoir to provide around 0.2 GWh of additional storage. He also underlined that more than €100 million have been invested in environmental mitigation to secure stakeholder trust.

During the debate, Romain Pellegrino stressed that hydropower “remains crucial to balance variable renewables” and warned that regulatory frameworks in Europe are not keeping pace with system needs. Elena Vagnoni shared findings from the XFLEX-HYDRO project, noting that digitalisation and real-time optimisation can “increase efficiency, reduce fatigue, and extend equipment lifetime.” Danilo Moresco emphasised ABB’s investment in innovation, highlighting the role of digital twins, cloud-based architectures, and AI, while underlining the need for “collaboration across utilities, startups, and universities.”

From India, Parveen Nanda presented the Pinnapuram Integrated Renewable Project, the world’s first large-scale combination of 4.5 GW of wind, solar, and PSH under a single grid connection. He explained that hybrid approaches, including batteries and advanced sensors, were essential to keep costs manageable while providing flexibility.

Looking ahead

The session confirmed that pumped storage is far from a “done and dusted” technology. From digitalisation and hybridisation to new partnership models, innovation is reshaping the sector worldwide.

By co-moderating this high-level debate, ETIP HYDROPOWER reaffirmed its leadership in advancing hydropower innovation in Europe, while connecting with global pioneers shaping the clean energy transition.

ETIP HYDROPOWER participated as BRONZE Partner at the International Forum on Pumped Storage Hydropower, held at UNESCO Headquarters in Paris. This high-level global event marked the culmination of a year-long campaign from the International Hydropower Association (IHA) to accelerate action on pumped storage hydropower: the “unsung hero” of the energy transition.

At the Forum, ETIP HYDROPOWER, together with Di-Hydro and STOR-HY, represented the ETIP HYDROPOWER Cluster on the exhibition hall, gathering together some of the most ambitious European projects dedicated to advancing hydropower technology and energy storage solutions. The cluster showcased the latest EU Horizon Europe projects, including: iAMP-Hydro, D-Hydroflex, SHERPA, HYDRO4U, ReHydro, RevHydro, XFLEX-HYDRO, HYPOSO, Store2Hydro, and H-HOPE. Together, these projects embody Europe’s leadership in developing sustainable, flexible, and environmentally responsible hydropower systems.

The Forum took place at a critical moment for global climate action. At COP29, 58 nations committed to the Global Energy Storage and Grids Pledge, setting the ambitious target of deploying 1,500 GW of energy storage, doubling grid investments, and expanding 25 million km of new grid infrastructure by 2030. Hydropower—and particularly pumped storage, which already accounts for around 90% of global long-duration energy storage—will play a decisive role in making these targets a reality.

Despite its proven value and relatively small environmental footprint, pumped storage remains largely unknown to the public. The IFPSH gathered Heads of State, Ministers, CEOs, financial institutions, intergovernmental organisations, and industry leaders to raise awareness and agree on the policies and practices needed to unlock new development.

ETIP HYDROPOWER has signed the Paris Pledge on Pumped Storage Hydropower by IHA and Eurelectric, becoming an official supporting partner of this important initiative presented at the International Forum on Pumped Storage Hydropower in Paris on the 9th of September 2025.

The Paris Pledge acknowledges the urgent and growing need for long-duration electricity storage to ensure a reliable, affordable, and sustainable energy system in Europe. As variable renewable energy sources are projected to reach 86% of Europe’s generation capacity by 2050, the demand for flexibility will increase sevenfold, exceeding 2,000 TWh annually compared to 310 TWh today.

Pumped storage hydropower (PSH), which already represents over 90% of global electricity storage capacity, is identified in the pledge as the most important, scalable, and cost-effective long-duration storage solution available today. Expanding Europe’s PSH capacity is described as essential to:

• Enable large-scale integration of wind and solar power, reducing curtailment (over 12 TWh of renewable electricity was curtailed in 2023, costing €4.3 billion)
• Stabilise electricity markets by lowering peak prices and system costs
• Enhance resilience and provide recovery capacity after blackouts
• Strengthen European supply chains and create economic opportunities;
• Contribute to climate adaptation through water management solutions

By supporting the pledge, ETIP HYDROPOWER reinforces its role in advancing evidence-based knowledge, innovation, and dialogue to accelerate the deployment of pumped storage hydropower in Europe.

“In his Research and Innovation Agenda as well as in the Strategic Industry Roadmap, ETIP HYDROPOWER has identified pumped storage hydropower as a vital contribution to the safe energy transition in Europe.”

-Anton Schleiss. 

You can read the full pledge here

The latest special issue of HYDROLINK (2/2025), published by the International Association for Hydro-Environment Engineering and Research (IAHR), sheds light on the vital and evolving role of pumped storage hydropower (PSH) in global energy systems. Over the past fifty years, PSH has expanded significantly—initially serving as a solution to store surplus energy from thermal and nuclear plants during low-demand periods, and more recently, as a flexible backup to address the intermittency of wind and solar generation.

Several experts from the ETIP HYDROPOWER Forum contributed their insights and research to this special edition, emphasizing PSH’s critical role in supporting a secure and sustainable energy transition:

• Pumped Storage Hydropower in Arid Climates: A Crucial Asset for Energy Transition. Benoît Houdant and Thomas Pinchard (EDF) explore how PSH projects in water-scarce regions can enhance grid stability while contributing to renewable integration. Read more. 
• Design Challenges in the Renaissance of Pumped-Storage Hydropower to Support the Energy Transition. Anton Schleiss (ETIP HYDROPOWER, EPFL) examines the engineering and environmental challenges driving modern PSH development. Read more.
• The Critical Role of Power Intake/Outlet Structures in Pumped Storage Schemes: Design Challenges and Optimization. Azin Amini and Giovanni De Cesare (EPFL) highlight the significance of hydraulic structures in optimizing PSH scheme efficiency and reliability. Read more.
• Pumped-Storage Technology: Fixed vs. Variable Speed. Michael Schmid (Andritz) analyzes the benefits and limitations of fixed and variable speed technologies in modern PSH plants. Read more.

This special issue underscores the strategic importance of pumped storage hydropower as a cornerstone technology for a decarbonized and resilient energy future. Access the full issue at HYDROLINK 2/2025.

The Di-Hydro Project is pleased to announce its First Project Workshop, an interactive online event dedicated to exploring how digital technologies can drive innovation within the hydropower sector. The workshop is designed to encourage knowledge-sharing and meaningful discussions on how digitalisation can support the development of hydropower both within the Di-Hydro Project and across the broader industry.

As part of its commitment to advancing the potential of hydropower plants and clusters, the Di-Hydro Project seeks to transform the operation of hydropower facilities through the integration of digital technologies—making them more intelligent, efficient, and environmentally sustainable.

Event Details:

• Date: 25 July 2025
• Time: 15:00–16:00 CEST
• Location: Online (Participation is free of charge; registration is required)

Professionals, researchers and stakeholders with an interest in hydropower and digitalisation are warmly invited to attend. The workshop will provide a valuable opportunity to exchange insights, explore current trends, and discuss future applications of digital solutions in the hydropower sector.

Registration is open until 24 July 2025 and can be completed via the following link: Register here.

Hydropower generation in Europe surged to its highest level in a decade in 2024, reaching 680 terawatt-hours (TWh), as the continent experienced exceptional rainfall and accelerated its transition toward renewables, according to the 2025 World Hydropower Outlook released yesterday by the International Hydropower Association (IHA).

The report highlights a landmark year for Europe’s energy system, with hydropower, wind, and solar dominating the EU’s power mix. Hydropower alone generated 13% more electricity than the average output from 2014 to 2017. The increased output underscores hydropower’s critical stabilising role in a volatile energy landscape marked by shifting markets and growing security concerns.

Total installed hydropower capacity in Europe rose to 262.7 gigawatts (GW) in 2024. The continent also saw growing interest in pumped storage hydropower (PSH)—the most proven large-scale electricity storage technology—as policy momentum builds. Europe’s PSH development pipeline now stands at 52.9GW, supported by EU-level reforms and national mechanisms designed to ensure long-term grid flexibility.

The EU’s 2024 electricity market reform mandates member states to evaluate flexibility needs over five- to ten-year horizons, while national initiatives such as the UK’s Cap & Floor regime and capacity markets in Italy and Spain are drawing developers and investors alike.

“With market volatility and system stress on the rise, pumped storage is gaining the attention it deserves,” said Eddie Rich, CEO of the IHA. “The story of this year’s Outlook is clearly that pumped storage hydropower is at the forefront as the world looks to expand energy storage.”

IHA President Malcolm Turnbull added: “Encouragingly, this year’s World Hydropower Outlook shows that global new capacity is accelerating after several years of stagnation. Continued momentum will require bold policy action, including reforms to reward hydropower’s multiple benefits, and faster permitting. The only resource we lack is time.”

On the ground, significant PSH activity is underway across Europe:

• United Kingdom: Over 13GW of PSH projects announced and in development.
• Austria: Around 1.3GW under construction, with 2.8GW in early development.
• Italy: Pipeline nearing 4GW.
• Greece: Over 3GW of PSH in development.
• Türkiye: Nearly 600MW of conventional hydropower under construction.

The total pumped storage installed capacity in Europe now stands at 56GW, with 201MW added in 2024.

Globally, hydropower added 24.6GW of new capacity in 2024—including 16.2GW from conventional and 8.4GW from pumped storage. The development pipeline now exceeds 1,075GW, with 600GW of PSH and 475GW of conventional hydropower.

As hydropower continues to anchor Europe’s renewable transition, the message from this year’s Outlook is clear: investment, policy, and urgency must align to ensure the region’s power systems remain reliable, flexible, and low-carbon.

Download and read the report here

Experts from across the hydropower sector gathered in Gaustablikk, Norway on May 21, 2025, for a full-day working meeting of IEA HYDRO Task 9. Hosted by Atle Harby and Linn Emelie Schäffer, the meeting brought together researchers and industry professionals to present their latest findings and strategize on the future direction of hydropower's role in energy systems—particularly in supporting flexibility, storage, and integration with other renewable technologies.

Presentations Highlight Flexibility, Storage, and Economic Valuation

The meeting began with updates from Task 9 leads before moving into a series of technical presentations focused on surplus energy, flexibility metrics, and valuation methodologies:

• • Luke Middleton opened with an analysis of surplus energy availability in modern grids.
  • Abhishek Somani expanded on this topic with a focus on flexibility metrics.
  • Linn Emelie Schäffer delved into how these metrics can be used to evaluate hydropower’s role.
  • Carl Andreas Veie discussed the concept of value factors for hydropower plants.
  • Seamus Garvey presented on medium-duration energy storage options.

Strategic Discussions on Ongoing and Future Tasks

In the second half of the meeting, members provided updates on various sub-topics within Task 9:

Status reports were shared on hydropower hybrids, flood control and drought management, and broader themes of flexibility and storage.

• • Yoichi Miyanaga presented insights from Japan on pumped storage hydropower, proposing a new sub-task to explore its full potential.
  • The group also discussed the concept of value-adjusted Levelized Cost of Electricity (LCOE) and questioned hydropower's exclusion from the IEA World Energy Outlook (WEO), suggesting future engagement with IEA Paris.
  • Updates on long- and medium-duration energy storage and collaboration with the IEA Wind Technology Collaboration Programme (TCP) were also presented.

Looking Ahead: Focus Areas for Task 9

Task 9 members agreed to prioritize several key areas moving forward:

• • Continued focus on long-duration flexibility and storage, reinforcing hydropower’s value in stabilizing future power systems.
  • Development of hydropower hybrids and further exploration into their role in grid integration.
  • Enhanced collaboration with Wind TCP to explore cross-technology synergies.
  • Increased emphasis on the valuation of hydropower services, including market-based storage roles, spot and forward pricing, and reservoir level impacts.
  • Dissemination through workshops, webinars, journal articles, and factsheets to share findings and stimulate dialogue within the broader energy community.

For more information on the Task 9 and its work, check out their reports and website here.

30 Energy Experts from 11 European Countries have Gathered to Visit One of Europe’s Most Advanced Pumped Storage Projects Under Development

ETIP HYDROPOWER—with the support of ANDRITZ and VOITH—organised an exclusive site visit to the Kühtai 2 Pumped Storage Power Plant, developed by TIWAG-Tiroler Wasserkraft AG (TIWAG), on 6 June 2025. The visit brought together 30 energy experts from 11 European countries, fostering dialogue and knowledge sharing across the hydropower sector.

Hosted and guided by TIWAG, the visit offered participants direct insight into one of Europe’s most advanced pumped storage hydropower (PSH) projects currently under construction, along with the opportunity to engage with the engineers and specialists leading its development.

Recharging Europe’s Energy System

Electricity storage remains the essential pillar of the energy transition, enabling the integration of variable renewable energy sources, enhancing security of supply and reducing reliance on imported fossil fuels. In this context, Pumped Storage Hydropower has emerged as a proven, reliable, and large-scale storage solution and will play a key role in securing a sustainable and resilient European energy future. 

With several gigawatts of PSH under construction and tens of gigawatts in the pipeline across Europe, the region is experiencing a revival of investment and innovation in this field. Europe stands not only as a growing PSH market but also as a global hub for hydropower excellence.

"Pumped storage hydropower is essential for grid stability, system flexibility, and the large-scale integration of renewables. Kühtai 2, developed by TIWAG, exemplifies how this proven technology can contribute to Europe’s clean and resilient energy future. 

As a key partner in this flagship project, Voith Hydro contributes with cutting-edge technology, deep expertise and long-standing commitment to collaboration across the industry.”

— Radu Carja, Chief Sales Officer, Voith Hydro

“Thank you to ETIP HYDROPOWER and TIWAG for the opportunity to gain such impressive insights into Europe’s largest dam construction sites. ANDRITZ is supplying two cutting-edge motor generators for this key plant, and ETIP HYDROPOWER is fulfilling its role as a European hub by offering stakeholders access to state-of-the-art technology and valuable exchange.

This project is a crucial building block. Without hydropower and pumped storage, Europe’s energy transition cannot succeed. It’s not just about supply security, but also about using domestic resources, creating European added value, and strengthening know-how.”

— Peter Stettner, ANDRITZ Hydro and Co-Chair of the ETIP HYDROPOWER Governing Board

A Glimpse into the Kühtai 2 project 

Located in Tyrol, Austria, Kühtai 2 is being developed by TIWAG and is part of the expansion of the Sellrain-Silz power plant group. The plant is equipped with two variable-speed pump-turbine units of 95 MW each and full-size frequency converters, making it one of the most advanced flexible generation assets in Europe.

The newly built Kühtai reservoir and the additional natural inflow from the Ötztal and Stubaital valleys will significantly enhance the plant's generation capabilities, allowing it to flexibly store and dispatch renewable electricity on demand.

As Europe advances toward a more sustainable and resilient energy system, projects like Kühtai 2 underline the indispensable role of hydropower and the importance of cross-sector collaboration and stakeholder engagement.

Click here to access to the press release of the visit

ETIP HYDROPOWER members took part in the 28th Congress and 93rd Annual Meeting of the International Commission on Large Dams (ICOLD), held in Chengdu, China. The event brought together experts, policymakers, and institutional stakeholders from across the globe to discuss the role of dams and hydropower in addressing key global challenges, including energy transition and climate change adaptation.

Denis Aelbrecht, Chair of the ETIP HYDROPOWER Governing Board; Sera Lazaridou, Member of the Governing Board; and Anton Schleiss, Secretariat and Scientific Coordinator, participated to the ICOLD General Assembly as Chairman of French National Committee, Chair of EURCOLD and Chair of ICOLD Technical Committee as well as Honorary ICOLD President to the 28th ICOLD Congress and 93the Annual Meeting in Chengdu, China. 

A significant outcome of the Congress was the endorsement of the World Declaration on “Dams and Reservoirs for Energy Transition and Adaptation to Climate Change.” The declaration was jointly signed by several leading international organizations, including ICOLD, the International Hydropower Association (IHA), IEA HYDRO, the International Commission on Irrigation and Drainage (ICID-CIID), the World Water Council, and IME.

As part of the official programme, Anton Schleiss presented an overview of the recent progress and achievements of ETIP HYDROPOWER during the meetings of the EURCOLD Board and the ICOLD General Assembly. 

ETIP HYDROPOWER’s active participation at this high-level event underscores its ongoing commitment to unifying the hydropower sector and fostering the Research and Innovation Agenda.

Read the full World Declaration here