Ethohydraulic experiments on the fish protection potential of the hybrid system FishProtector at hydropower plants

Fish behaviour investigations under controlled laboratory conditions but nature like environment were conducted to clarify the efficiency of inclined and horizontal screen planes for fish protection and fish downstream passage at hydropower plants concerning different potamodromous species and various sizes. The dependency on the underlying geometric and hydraulic parameters was investigated and comprehensive models were deduced to describe these relations. Adequate geometric and hydraulic design could achieve high levels of fish protection and downstream passage efficiency, even for small fish, weak swimmers and riverbed/bottom oriented species. The results imply good transferability and accordance with field observations at large scale facilities and can provide valuable information for facility design.

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Swimming Behavior of Downstream Moving Fish at Innovative Curved-Bar Rack Bypass Systems for Fish Protection at Water Intakes

Water ◽

10.3390/w12113244 ◽

2020 ◽

Vol 12 (11) ◽

pp. 3244

Author(s):

Claudia Beck ◽

Ismail Albayrak ◽

Julian Meister ◽

Armin Peter ◽

Oliver M. Selz ◽

...

Keyword(s):

Fish Species ◽

Flow Direction ◽

Cost Effective ◽

Technical Solution ◽

Velocity Increase ◽

Hydropower Plants ◽

Downstream Flow ◽

High Fish ◽

Fish Protection ◽

Run Of River

New types of fish guidance structures with vertical curved bars and a subsequent bypass system represent a promising technical solution for the protection and guidance of downstream moving fish at run-of-river hydropower plants and water intakes. These so-called “curved-bar rack bypass systems” (CBR-BSs) function as a mechanical behavioral barrier and are characterized by low hydraulic losses, a symmetrical downstream flow field and an overall high fish guidance efficiency in the laboratory for a wide array of European freshwater fish species. This paper presents the results of the hydraulic and live-fish laboratory tests of an optimized CBR-BS configuration with a bar spacing of 50 mm and 30° rack angle to the flow direction. The tests were conducted with six different fish species in an ethohydraulic laboratory flume at different approach flows (0.5 m/s, 0.7 m/s) and different bypass entrance velocities (0.6–1.0 m/s). A numerical model was used to simulate the flow fields in the CBR-BS in order to link the fish behavior to the hydrodynamic cues created by the CBR-BS. Lower approach flow velocities decreased the hydraulic cues of the CBR, which led to more rack passages. A 20% velocity increase towards the bypass entrance significantly increased the fish guidance efficiency compared to a 40% velocity increase. The tested CBR-BS resulted in overall higher interspecies fish protection and guidance efficiencies compared to the more commonly applied horizontal-bar rack with a narrow bar spacing of 20 mm. Recommendations for a sustainable and cost-effective application of CBR-BSs are given.

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Head Losses of Horizontal Bar Racks as Fish Guidance Structures

Water ◽

10.3390/w12020475 ◽

2020 ◽

Vol 12 (2) ◽

pp. 475 ◽

Cited By ~ 1

Author(s):

Julian Meister ◽

Helge Fuchs ◽

Claudia Beck ◽

Ismail Albayrak ◽

Robert M. Boes

Keyword(s):

Flow Field ◽

Fish Passage ◽

Head Loss ◽

Hydraulic Performance ◽

Velocity Fields ◽

Hydropower Plant ◽

Protection Measures ◽

Head Losses ◽

Hydropower Plants ◽

Fish Protection

Horizontal bar racks have been used as trash racks at hydropower plants since the 1920s. With the installation of the first horizontal bar rack bypass system at a hydropower plant as a downstream fish passage facility in 2006, these racks rapidly gained importance as fish protection measures. Since then, they have been installed at more than 100 small- to medium-sized hydropower plants in Europe. Despite the large number of installed racks, systematic investigations of the head losses and velocity fields were missing. On the basis of detailed hydraulic experimentation with a large number of rack parameters and including up-to-date foil-shaped bars, the layout of horizontal bar racks and their hydraulic performance were assessed in the current study. This paper reports the results of the rack head loss investigation, whereas the accompanying paper entitled Velocity Fields at Horizontal Bar Racks as Fish Guidance Structures focuses on the up- and downstream velocity fields. By applying foil-shaped bars instead of rectangular bars, the loss coefficient was reduced by more than 40%, depending on the rack configuration. Bottom and top overlays are used to increase the guidance efficiency for fish, sediments, and floating debris. However, the altered flow field results in increased head losses. A new set of equations is proposed to predict head losses for current horizontal bar racks, including overlays for various hydropower plant layouts. The predictions are compared to literature data.

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Run-of-the-River Hydro-PV Battery Hybrid System as an Energy Supplier for Local Loads

Energies ◽

10.3390/en14165160 ◽

2021 ◽

Vol 14 (16) ◽

pp. 5160

Author(s):

Dariusz Borkowski ◽

Dariusz Cholewa ◽

Anna Korzeń

Keyword(s):

Hybrid System ◽

Power Plants ◽

River Flow ◽

Hydropower Plant ◽

Construction Time ◽

Hydro Power ◽

Local Loads ◽

Energy Deficiency ◽

Hydropower Plants ◽

Hydro Power Plants

Hybrid hydro energy systems are usually analysed with pumped hydro storage systems, which can facilitate energy accumulation from other sources. Despite the lack of water storage, run-of-the-river hydropower plants are also attractive for hybrid systems owing to their low investment cost, short construction time, and small environmental impact. In this study, a hybrid system that contains run-of-the-river small hydro power plants (SHPs), PV systems, and batteries to serve local loads is examined. Low-power and low-head schemes that use variable-speed operation are considered. The novelty of this study is the proposal of a dedicated steady-state model of the run-of-the-river hydropower plant that is suitable for energy production analysis under different hydrological conditions. The presented calculations based on a real SHP of 150 kW capacity have shown that a simplified method can result in a 43% overestimation of the produced energy. Moreover, a one-year analysis of a hybrid system operation using real river flow data showed that the flow averaging period has a significant influence on the energy balance results. The system energy deficiency and surplus can be underestimated by approximately 25% by increasing the averaging time from day to month.

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Kryothermie-Hybrid-System mit intern gasgekühltem Applikator zur Radiofrequenzablation

RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren ◽

10.1055/s-2007-977319 ◽

2007 ◽

Vol 179 (S 1) ◽

Author(s):

H Rempp ◽

S Clasen ◽

M Voigtländer ◽

S Kempf ◽

A Weihusen ◽

...

Keyword(s):

Hybrid System

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Control of odor using an electrostatic precipitator andadsorption hybrid system in unregulated facilities

Journal of Odor and Indoor Environment ◽

10.15250/joie.2014.13.2.113 ◽

2014 ◽

Vol 13 (2) ◽

pp. 113-123 ◽

Cited By ~ 1

Author(s):

Hak-Song Jeon ◽

◽

Jong-Min Kim ◽

Kwang-Han Bae ◽

Tae-Oh Kim

Keyword(s):

Hybrid System ◽

Electrostatic Precipitator

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“Collective Redress” in European Competition Law

Zeitschrift für Wettbewerbsrecht ◽

10.15375/zwer-2016-0407 ◽

2016 ◽

Vol 14 (4) ◽

pp. 388-414

Author(s):

Alexandra P. Mikroulea

Keyword(s):

Hybrid System ◽

Competition Law ◽

Mixed System ◽

Basic Question ◽

Effective Implementation ◽

The United Kingdom ◽

Collective Redress ◽

Opt Out ◽

Private Autonomy ◽

European Competition Law

AbstractOpt-in or opt-out? That is the basic question to be answered. The decision to promote actions of “opt-in” type as opposed to those of the “opt-out” type, for the sake of private autonomy, does not ensure the effective application of european competition law. On the contrary, it may decrease the application’s intensity and effectiveness. Recent reforms among European state members such as in the United Kingdom, Belgium, the Netherlands, Denmark and Norway are powerful indications that the opt-out principle may result in the effective implementation of competition law. There is no doubt that a mixed system (hybrid system), providing the court with the power to decide in favour of either the opt-in or the opt-out system, will result in better implementation of competition law. At the present time there are two pending cases in England (Dorothy Gibson and Mastercard) for which the decision on opt-out or opt-in are highly anticipated. Should the court decide, in one or both of the cases, on an opt-out approach, this will bring a momentous reevaluation of the entire collective redress concept.

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