Environmentally Enhanced Turbines for Hydropower Plants: Current Technology and Future Perspective

Abstract

Environmentally enhanced turbines (EETs) have gained attention in the past two decades in order to reduce environmental impacts of hydropower plants on fish communities and on water quality. In this mini-review the main EETs are discussed, focusing on the Alden and Minimum Gap Runner turbines to reduce fish injury and on self-aerating and self/free-lubricant turbines to improve water quality. The review shows that EETs can be efficiently adopted instead of traditional turbines: EETs are cost-effective, efficient in terms of energy generation and have shown to reduce environmental impacts. Scientific gaps are also highlighted and case studies reported to better support refurbishment and new projects.

Advanced Manufacturing and Materials for Hydropower: Challenges and Opportunities

“…In hydropower, bearings and lubrication are needed in several components, but most importantly in the powertrain and gates. In particular, hydraulic turbines are filled with pressurized petroleum-based mineral oil to lubricate all the bearings of the runner hub, blades, and all the sliding parts (Quaranta et al 2021). As discussed in St-Germain (2018), oil leakage from hydropower runners causes operational issues and has serious environmental impacts on the local aquatic ecosystem.…”

State of the Art in Designing Fish-Friendly Turbines: Concepts and Performance Indicators

“…Reference source not found.i, which are found to have an efficiency of up to 50%, whereas the estimated survivability through them is of more than 98% [127]. Finally, some additional factors, even if not directly related to turbine technologies/subsystems, still affect fish mortality [128]:…”

Numerical design methodology for reversible Deriaz turbine with high energy performance and reduced fish impacts

“…The hydraulic and the mechanical design of hydro turbines involve several parameters that may affect the impacts on the passing fish and their survival rates. These impacts depend mainly on the turbine type and specific speed, and have been widely studied in literature [1,2]. Mechanical damages (strike on walls and blades), abrupt pressure changes (barotrauma), high shear stresses and turbulence, and cavitation can cause external and internal injuries to passing fish [3].…”

“…Mechanical damages (strike on walls and blades), abrupt pressure changes (barotrauma), high shear stresses and turbulence, and cavitation can cause external and internal injuries to passing fish [3]. The quantification of these effects and their correlation with the mechanical/hydrodynamic design of the turbines in order to reduce the probability of injuries and mortality are still being studied by several researchers [1][2][3][4][5] and the industry [6], though some more 'fish-friendly' turbines have been proposed in the past decades, e.g. [7][8][9].…”