The double rotating hydropower screw

Fish ladder + fish descent + electricity generation


The patented, gap-free hydropower screw including the fish lift makes injury-free fish migration possible as well as the movement of microorganisms and sediment past transverse structures with simultaneous electricity generation.

Details for the fish bypass

The fish ascent screw (FAS, mono-tube)

The economical alternative for fish ascent

With the fish ascent screw (FAS) Hydroconnect additionally offers a low cost solution for the creation of fish passage from downstream water to the upstream water.

Details for the fisch ascent screw

Benefits of the hydrodpower screw

Injury-free fish migration

Fish and other river life pass transverse structures and dams without injury and effortlessly.

Low space requirements

The thin hydropower screw requires a minimum amount of construction work, protects the riverbed and is integrated inconspicuously into the landscape.

High efficiency

Up to 70% electrical efficiency (=power output at electrical connector terminals) – even if the water level is low – thanks to the patented, gap-free and fish-friendly construction.

Scientific feedback (extract)

  • continuous ascents registered during the entire operating period (Oct. 2013 to March 2014)
  • The hydrodynamic screw from Hydroconnect is very well suited for fish descent
  • various fish species descended and ascended
  • no danger of injury for fish (upstream and downstream)

Fish ecological studies of the “HYDROCONNECT” hydrodynamic screw with an “Albrecht fishLift inside” at the Jeßnitz power plant location (2014)

BOKU – University of Natural Resources in Vienna, Institute for Hydrobiology and Water Management

The solution in use

Location Country River Maintainer Predominant fish Flow Drop height
GroßarlbachAustriaGroßarler Ache Energiebetrieb Hettegger GmbHtrout, grayling up to 80cm2.7m
ScheibbsAustriaErlaufEVN naturkraft GmbHDanube salmon, 80cm5,6m
AinringGermanyHammerauer MühlbachStahlwerk Annahütte Max Aicher GmbH & Co. KGDanube salmon, 100cm7.17m
Spittal on the DrauAustriaLieserLieser Energie GmbHDanube salmon, 80cm4.6m
BerndorfÖsterreichMürzNorske Skog Bruck GmbHDanube, 100cm6.6m

Frequently asked questions

How high is the efficiency of the Hydroconnect hydropower screw with double rotating cylinders?

The mechanical efficiency is up to 90%. This results in electrical efficiency, minus all the mechanical losses, of 65% even for small systems. In larger systems, the electrical efficiency increases to 70% and more.

With what water supply does the system work for electricity generation and fish migration?

The system can be used starting with a supply of 100 l/s. The highest flow rate is currently offered at 6,500 l/s. These systems are very well suited as residual water machines or as main machines for small locations.

What is the service life of a hydrodynamic screw with double rotating cylinders?

The HYDROCONNECT hydropower screw with double rotating cylinders is calculated for fatigue strength. The selected corrosion allowance with the choice and thickness of material ensures a minimum service life of 30 years.

Has 100% freedom from injury been proven by recognised centres for all river life?

Yes, of course. All research programmes and monitoring studies were accompanied by the Institute for Hydrobiology and Water Management (HG) at the University of Natural Resources in Vienna (BOKU). 100% freedom from injury was confirmed by BOKU in numerous studies.

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Your project

Additional questions? Contact your product account manager Nino Struska. He would be happy to answer your questions and help you during the planning and realisation.

Your personal product account manager

Nino Struska
+43(0) 720 720 900-850
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