Neptun - Low voltage fish protection

NEPTUN by Procom Systems is an electrical barrier that prevents fish from entering hydraulic structures or can be used as a migration barrier.

The efficiency of the system was evaluated by Wroclaw University of Environmental and Life Sciences and Inland Fisheries Institute in Olsztyn (Żabieniec Branch) as a part of the Sector Operational Program "Fishery and Fish Processing 2004-2006".

I AM HYDRO is the distributor of NEPTUN in Germany, Austria, and Switzerland. We advise, plan together with experts from Procom Systems and deliver a fish guidance system adapted to your project.

Advantages of the NEPTUN system

  • Easy installation and retrofitting on existing but also newly constructed facilities (independent of water width, depth or type of riverbed)
  • No restriction of the shipping
  • No influence on the height of fall
  • Resistant to icing
  • Low energy consumption
  • High safety aspect due to operation in the low-voltage range with direct current


Transverse structures and hydropower plants 
A Neptune fish guidance system installed in the backwater prevents fish from getting into turbines by reversing their migration direction or ensuring a safe descent through fish passes.
A Neptune fish guidance system installed in the tailwater prevents ascending fish from swimming into the strong-flowing, oxygen-rich turbine outlets and guides them into fish passes.
The Neptune fish guidance system helps ensure the ecological connectivity of running waters required by the Water Framework Directive (WFD), prevent animal suffering and reduce damage to power plant facilities.

Above-ground water collection
The Neptune Fish Guidance System protects technical facilities that need to collect water from water bodies above ground for cooling power plants or for the extraction of process water. Many animals die in pumps. With a lot of effort, water extraction plants have to be cleaned. The Neptun Fish Guidance System protects fish and plants.

Protection of water bodies
The Neptune system can also be used as a migration barrier. This can prevent invasive species from entering sensitive aquatic ecosystems or protect fish farms from predators.

The Neptune system produces a heterogeneous non-linear electric field in the water, which can be used to control the behavior of fish. The nerves and muscles of fish are influenced to make them move away from the field. Constant changes in the field parameters prevent the fish from adapting. The electric field poses no risk to animals or humans.

This technique has been used for decades, although in the opposite direction, in electrofishing for stock assessment and regulation as well as evacuation, where it has proven to be a reliable method.

The technical parameters of each NEPTUN system depend on the hydrotechnical characteristics of a plant and the water body. After collecting all relevant information, PROCOM SYSTEM experts perform calculations to determine the optimal size of the required electric field at which the highest efficiency can be achieved with the lowest energy demand.

Required data for planning:
  • Construction plans of the plant with positions of turbines, fish pass, or water supply points
  • Water depth
  • Conductivity
  • Condition of the water bottom
  • Flow velocity
  • Position of the power supply for the NEPTUN system (optimal: three-phase connection)

NEPTUN can be used not only as a fixed installation in a plant but also as a portable version.

The NEPTUN system is installed in a large number of plants worldwide. Its purpose is to protect and monitor migratory fish. Below are some examples:



Hydropower plant at the Madeira, Jirau



Diversion of migrating sea lamprey in fish traps, Bridgeland Creek (portable NEPTUN)
Fish barrier in Lake Ontario



Fish protection nuclear power plant Philipsburg, Rhine
Fish protection waterpower plant Gaggenau, Murg
Fish protection waterpower plant Mühlhausen, Enz
Fish protection water intake Wiesbaden, Rhine



Hydropower plant at Widawka, Szczerców
Hydropower plant at the Drzewiczka, Drzewica
Hydropower plant on the Wisłok, Rzeszów
Hydropower plant on the Odra river, Kędzierzyn Koźle
Hydropower plant on the Wisła, Smolice
Monitoring of the effects of the "Plan of development of eels in Poland" (portable NEPTUN system).
Dam in the Bóbr, Krzywaniec



Hydropower plant in Lake Geneva, Veytaux



Fishways Global
Diversion of migrating sea lamprey in fish traps, Hammond Bay Biological Station, USGS, Great Lakes Science Center, Millersburg (portable NEPTUN)
Diversion of migrating sea lamprey in fish traps, Silver Creek River, Ocqueoc River, Michigan (portable NEPTUN).

Further information is available here.