The European Union’s hydropower sector is entering a period of rising operational demands, slow capacity growth and increasing strategic importance, according to the European Commission’s latest Clean Energy Technology Observatory (CETO) assessment. The report highlights hydropower’s central role in system flexibility and water management, while underscoring environmental and financial constraints that continue to limit expansion.
Hydropower remains the EU’s second-largest source of renewable electricity, with 153GW of installed capacity in 2023 generating roughly 300 TWh annually. Pumped-storage hydropower (PSH) adds 46GW of turbine capacity, representing nearly a quarter of global PSH installations. Together, reservoir hydropower and PSH remain the backbone of Europe’s long-duration energy storage, more than 90% of global storage outside traditional reservoirs still comes from PSH, the report says.
CETO notes that the EU’s hydropower fleet is aging (average plant age is about 45 years) and now experiences rapidly increasing stop-start cycling as grids absorb more variable wind and solar output. The report warns that this operational stress demands higher investment in refurbishment, digital control systems and modern electro-mechanical equipment. Upgrading existing assets could lift annual generation by up to 40TWh, the equivalent output of several large new plants, without expanding river fragmentation.
Despite hydropower’s maturity and high efficiencies (often exceeding 80–90%) the EU added only around 6GW of new capacity in the last decade, reflecting limited remaining economic sites and stricter environmental requirements. Public RD&I investment has ranged from €8–22m annually over the past decade, while the European Commission contributes roughly €10m per year through Horizon Europe programmes.
The report highlights strong industrial competitiveness: EU companies hold nearly half of high-value global hydropower inventions and account for 47% of global turbine and component exports when intra-EU trade is included. However, the real scale of Europe’s hydropower supply chain is far larger than trade statistics indicate. When factoring the hundreds of components required in hydropower construction, the combined annual production value of the EU’s top industrial countries exceeds €130bn, far above the €562m captured by turbine-specific trade codes.
Environmental pressures remain a defining challenge. The EU hosts approximately 25,000 hydropower plants, but hydropower accounts for only a fraction of the 450,000 barriers in European rivers. The report stresses that new projects must minimise ecological impacts, improve fish passage and address reservoir sedimentation, which removes roughly 0.7% of storage volume annually.
Climate change is expected to deepen regional disparities: inflows could decline 20–31% in Southern Europe while increasing 14–21% in the North. CETO identifies modern reservoir management, pumped-storage expansion and hybridization with floating PV and battery storage as key tools for adaptation.
Looking ahead, PSH remains the largest growth opportunity. Studies cited in the report indicate 70–75GW of EU PSH capacity could be feasible by 2050, supported by reservoir interconnection, repurposed mines and modernization of existing assets. But lengthy permitting, limited revenue recognition for flexibility services and competition from rapidly expanding battery storage continue to weigh on investment decisions.
The report concludes that while hydropower is “the flagship of renewables in the EU,” sustained competitiveness will depend on modernisation, environmental performance, and market reforms that properly value long-duration flexibility and water-related services
