Retrofitting Europe’s hydropower fleet for safe fish passage: A pathway to EU eel escapement targets

Most EU hydropower plants are several decades old, [Quaranta et al., 2021] and the time is approaching, or has passed, when replacement of much of their major electromechanical equipment is required, on engineering grounds alone. New turbine runners installed during this replacement process are expected to remain in service for another 30-40 years. Therefore, the choices made by plant owners will have a major impact on turbine-related eel mortality across Europe for many years [European Union, 2007]. Until recently, turbines designed to improve fish survival were thought to reduce generating capacity, but recent design work at a 940 MW station on the St. Lawrence river in North America suggests that this trade-off may no longer apply.