Pumped-Storage Power Plants at the Heart of the Energy Transition
Ensuring the strength of France’s promises — from today to tomorrow
In its exploration of the conditions for a successful energy transition, the TerraWater Institute has highlighted the key role of pumped-storage power plants (PSPs), both for their contribution to the electrical system and to the hydrological system.
Because adopting this solution represents both an opportunity and a responsibility, the TerraWater Institute proposes several avenues for action that can be taken up by those committed to advancing the interests of local regions.
Since its creation, the Institute has chosen to focus on the potential of hydropower, and in particular on pumped-storage technology, given its decisive importance for the success of the energy transition and its multiple co-benefits.
This report serves as an initial collection of ideas, designed to evolve through successive editions, with the aim to:
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Contribute to discussions on France’s energy transition by highlighting a technology—already well mastered in France and across Europe—that is efficient, sovereign, and sustainable for any low-carbon electrical system: pumped-storage power plants.
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Reiterate key technical facts (Volume 1).
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Reintroduce into the national debate the significant potential for new hydropower generation facilities in France (Volume 2 – Pyrenees, Volume 3 – Alps, and Volume 4 – Massif Central and Jura).
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Support the assumptions of the TerraWater Scenario, first published in November 2022 and currently being updated for 2026, through which the integration of PSPs into the national electrical system takes on its full meaning.
Engaging with citizens, economic and political decision-makers, and local elected officials from the regions discussed in our report is, in our view, essential to better assess the real potential for new hydropower developments and their implications. These projects cannot be meaningfully considered beyond the conceptual stage without the involvement and approval of those who may one day bear responsibility for them.
Our sole role and intention are to enrich the debate and to provide a technical perspective on the challenges of the energy transition within our territories, so that citizens and decision-makers alike can make informed choices regarding the issues that affect them directly.
Download the reports (French) :
Rapport STEP
10/2025
Rapport STEP
10/2025