The Status of Environmentally Enhanced Hydropower Turbines

Abstract

Environmentally enhanced hydroelectric turbines have been developed to reduce injury and mortality of downstream‐migrating fishes and to improve downstream water quality. Significant progress has been made in the past decade in the development of such turbines and in the methods to evaluate their biological and power generating performance. Full‐scale demonstrations have verified the performance of Voith Hydro's minimum gap runner turbine, which maintains high survival rates for fish while producing more power than conventional designs. Despite a promising pilot study and subsequent design enhancements, similar full‐scale demonstrations of the fish‐friendly Alden turbine have yet to be conducted. Furthermore, the tools with which to predict and evaluate the performance of new turbine designs are available and are continually being improved. This article provides a status update of advances in this field over the past decade.

Burbot and large hydropower in North America: benefits, threats and research needs for mitigation

“…Initial work suggests new turbine designs can pass fish well (>98% survival of <20 cm fish) and actually improve power output (Hogan et al . ), but effects on burbot are yet to be quantified.…”

“…Thus, research to test the burbot passage mortality of new turbine designs will be important, particularly for ELS. Initial work suggests new turbine designs can pass fish well (>98% survival of <20 cm fish) and actually improve power output (Hogan et al 2014), but effects on burbot are yet to be quantified.…”

Evaluation of external fish injury caused by hydropower plants based on a novel field‐based protocol

“…Resulting injuries include scale loss, fin damage, haemorrhages, bruises, skin wounds, amputations of body parts or internal injuries, such as swim bladder rupture and emboli (Dedual, ; Ebel, ; Schneider, Hübner & Korte, ). As movement and migration are obligatory elements in the life cycle of many fishes (Lucas, Baras, Thom, Duncan & Slavík, ), the injuries and mortalities resulting from passage through turbines are still a major drawback of hydroelectric energy (Hogan, Čada & Amaral, ).…”

“…The severity of the impact of power plant passage is dependent on technical characteristics such as the rotation speed of the turbine, turbine diameter, number of turbine blades, blade angle and the drop height, which determine the degree of pressure changes, shear stress, cavitation and the collision risk for fish (Ferguson, Ploskey, Leonardsson, Zabel & Lundqvist, ; Skalski et al., ). Conventional power plants are often equipped with Pelton, Kaplan or Francis turbines, which are known for very high fish mortality due to their high rotation speed, pressure changes and shear forces (Hogan et al., ).…”

“…Currently, there is increased effort towards development of more fish‐friendly hydropower installations, including fish protection screens in combination with bypass systems at conventional turbines, as well as innovative turbine types. Innovative turbine types such as the very‐low‐head turbine or Archimedes screw turbines are supposed to be more “fish‐friendly” than conventional turbines (Hogan et al., ), but scientific evidence on lethal and sub‐lethal effects of these power plants on fish is still scarce. Single mechanisms causing damage to the fish body, such as pressure changes, have been intensively studied in the laboratory and in mathematical models (e.g.…”