Europe’s hydropower sector commits to doubling its pumped storage capacity

Electricity storage has become one of the greatest challenges of Europe’s energy transition. With forecasts indicating that by 2050 variable renewables will account for 86% of generation capacity, the hydropower industry has taken a step forward with a collective pact to double Europe’s pumped storage capacity within 25 years, unveiled in the French capital. The Paris Pledge – signed in early September by Zabala Innovation and more than 50 actors across the value chain – argues that only an accelerated roll-out of this technology will ensure energy security, contain prices, and reduce dependence on imported fossil fuels.

Through its direct support, Zabala Innovation aims to demonstrate its commitment to the energy transition ecosystem and to research and innovation efforts. As Erik Zabala, CEO of the consultancy, explained: “A central element of the Paris Pledge is the empowerment of the workforce, something that is fully aligned with the company’s mission. By supporting renewable technologies, Zabala Innovation also acts as a driver of skills, training and human capital development, fostering innovation and strengthening expertise throughout Europe’s clean energy transition.”

The consultancy’s endorsement of the document is directly linked to the European projects in which it actively participates. Zabala Innovation is part of ETIP Hydropower, a sectoral platform that has also backed the initiative and played a key role at the International Forum on Pumped Storage Hydropower in Paris, where the pledge was presented. In that setting, the team showcased various hydropower innovation projects in which it is involved, further reinforcing its commitment to the energy transition and to technologies that bring flexibility and storage to Europe’s power system.

Flexibility demand

The Paris Pledge stresses that demand for flexibility in the power grid will increase sevenfold over the next 25 years. In this context, pumped-storage hydropower is presented as the central cog in the energy system, being “the most important, scalable and cost-effective long-duration electricity storage solution available,” according to the signatories. Today it accounts for more than 90% of global storage capacity, but the industry warns that the 48 gigawatts currently installed in the EU and Switzerland are insufficient to meet future needs.

The figures included in the pledge support this point. In 2023, more than 12 terawatt hours of renewable electricity were wasted, at an estimated cost to consumers of €4.3 billion. Without new projects, that figure could increase tenfold by 2030. At the same time, power markets are under dual pressure: a 50% rise in negative price episodes and average electricity costs that are twice as high as pre-2021 levels.

However, the current pipeline of projects points to growth on the horizon. The EU has initiatives under way amounting to more than 32 gigawatts, with a further three gigawatts in Switzerland, Norway and Turkey. Together, these could deliver over 700 gigawatt hours of storage capacity – equivalent to more than 10 hours of consumption in countries such as Spain and Italy. The document underlines that this roll-out would not only strengthen energy security but also stabilise prices, boost the European supply chain and create tens of thousands of jobs, especially in rural areas.

The pledge also highlights the need to match industrial efforts with a stable regulatory framework. At the European level, it calls for a specific initiative to accelerate electricity storage and for legislative proposals to distinguish between short- and long-duration solutions. It also urges the effective implementation of the RED III renewables directive and the reform of the electricity market. At the level of Member States, the agenda includes removing double taxation on storage, ensuring remuneration for system services, and introducing more agile permitting processes.

Dual role

The environmental dimension is also explicitly included in the roadmap. The signatories commit to “monitor, quantify and mitigate any potential environmental impact, adopting the best-in-class solutions and tools.” They also stress the need to involve local communities and policymakers from the early stages, with the aim of integrating projects into the territory and strengthening their social legitimacy.

The document recalls that pumped-storage hydropower is a dual-purpose technology. Not only does it store electricity, it also enables the management of water resources in a context shaped by climate change. For this reason, the pledge highlights its role in mitigating impacts, supporting recovery after natural disasters, and strengthening the resilience of power systems against potential blackouts.

The backdrop to the agreement is the urgent need to respond to an energy system that combines overproduction at certain times with scarcity at others. The signatories warn that without sufficient long-duration storage deployment, Europe risks remaining structurally dependent on imported fossil fuels and exposed to high price volatility. “Pumped-storage hydropower is a key strategic lever for Europe’s long-term decarbonisation, as well as for its energy security and economic resilience,” the text notes. It concludes with an urgent call to action: “The time to act is now.”