Policy, science and industry synergies to unlock hidden small hydropower in the European Union under the water-energy-society-ecosystem nexus

Hydropower developed in existing hydraulic infrastructures, water facilities and industries, including non-powered dams and weirs, wastewater treatment plants and water distribution networks, is known as “hidden hydro”. Although it avoids many of the socio-environmental disturbances that might be generated by conventional hydropower, coordinated actions among Policy, Science and Industry (PSI) for scaling hidden hydro remain fragmented. This paper examines recent European Union (EU) policy and research programmes, framed under the Water-Energy-Society-Ecosystem (WESE) nexus, and evaluates their capacity to stimulate investments in hidden hydro, with specific focus on small hydropower (SHP). By harmonizing existing literature, this study identifies an untapped EU's potential of hidden hydro of up to 15 TWh/year (approx. 30% of current SHP annual generation in the EU), excluding the potential of upgrading existing SHP systems. Realising this capacity could generate multiple socio-economic co-benefits beyond clean electricity for society, that were also quantified: employment, community engagement, research investments, market trade and industrial innovation, ultimately enhancing competitiveness. The findings underscore that effective PSI synergies are essential for fully appraising and exploiting hidden hydro's contribution to the WESE nexus, and for aligning EU policies and research agendas with this resource.

QUARANTA Emanuele; 

2026-03-12

ELSEVIER

JRC143121

2211-4688 (online),   

https://www.sciencedirect.com/science/article/pii/S2211467X26001409,    https://publications.jrc.ec.europa.eu/repository/handle/JRC143121,   

10.1016/j.esr.2026.102174 (online),