Retrofitting of Existing Bar Racks with Electrodes for Fish Protection—An Experimental Study Assessing the Effectiveness for a Pilot Site

Downstream-migrating fish in rivers tend to follow the main current, and are danger of swimming through turbines at run-of-river hydropower plants, possibly causing high mortality rates. To avoid these losses, must be prevented from entering turbines. Most existing vertical bar rack systems (used for turbine protection) however usually do not ensure proper protection due large spacings. FishProtector technology enables retrofitting racks (i.e., mechanical barrier) with additional electrodes create a hybrid barrier. The induced electric field water aims behavioral barrier prevent passage rack. In this study, ethohydraulic experiments investigate effect such on were performed. detail, fish-protection rate spacing 30 mm was tested five different scenarios: (i) without (reference), four electrified setups electrode spacings (ii) 80 mm, (iii) 120 (iv) 160 (v) 200 mm. A flow velocity 0.23 m/s chosen replicate situation planned pilot site. study conducted an outdoor laboratory flume using small several local riverine species, mostly cyprinids minnows. results show that mean could increased 62% reference setup up 96% setups.