• Pump and Turbine Configuration


    Optimized for Tidal Fence applications

  • The best economic solution for

    Tidal Fence Ocean Power

Ronamic Ocean Power Tidal Fence Pump and Turbine (PaT)

The RONAMIC Tidal Fence PaT is a typical application of the RONAMIC technology in Tidal Fence/Range Ocean Power. Because the RONAMIC positive displacement (hydrostatic) technology is highly scalable, this application can be delivered with rotors of 6 meters in diameter and 6 meters in length. Just as all other RONAMIC machines, the Tidal Fence PaT will have the lowest CAPEX and OPEX in its class due to the fact that all components are made of concrete (rotors and caisson) and synthetic diamond (bearings).

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  • Main features of the Ocean Power Tidal Fence PaT

    Based on the superior Positive Displacement principle (hydrostatic principle) as opposed to the kinetic flow principle.




    High energy conversion rate at varying head and varying water flow due to an advanced design of the rotors (RONAMIC Advanced Rotors).

  • Low cost due to a small number of low tech, non-corrosive and long-life components (mainly concrete).

  • Multi-functional: operates as a pump, turbine and water lock.

A tidal fence (also called tidal barrage or range) is a dam that - unlike a conventional dam - allows water to flow in both directions by following the tidal cycle, capturing the energy from water driven by tidal forces and moving in and out through the dam.


Đ¢idal fence power plants exist for as long as 50 years already and their number is growing as governments and energy companies increasingly recognize the vast potential of this energy source. The well-known and important tidal fence power stations are Rance and Sihwa Lake.


The economics of tidal fence projects strongly depend on the cost of the required civil structures on the one hand, and on the cost and efficiency properties of the installed turbines on the other. And the latter is exactly where the RONAMIC Ocean Power Tidal Fence Pump and Turbine offers superior characteristics when compared to traditional kinetic turbines.


RONAMIC Ocean Power Tidal Fence Pump and Turbine is made of two unconventionally shaped concrete rotors and a caisson with a special flow pattern and hollow spaces embedded in the concrete elements. On top of the overall high efficiency, this system performs very well at a variable head. The unique pumping functionality of the Tidal Fence PaT makes it possible to use the excess energy in the grid to increase the water level in the basin at high tide (for ebb generation). Much of this energy is returned during generation, because power output is strongly related to the head.

The basic principles of the RONAMIC technology already ensure a high degree of fish-friendliness. Depending on fish safety legislation in a particular country, the RONAMIC PaT can be equipped with additional features to meet any specific requirements and could include lowering nominal rotational speed (which also results in higher energy efficiency), a fish guidance system, hollow fish friendly rotors and external systems such as fish-friendly trash-racks and fish bypass systems.

Combined with a robust and reliable power take-off (PTO), this pump and turbine technology makes the RONAMIC Ocean Power Tidal Fence Pump and Turbine the best economic solution for Tidal Fence Ocean Power for many situations regarding the particular location, application and business case.

Main specifications:

  • Required water head: 1 to 10 meters
  • Energy conversion efficiency of the turbine: 70%-80%
  • Dimensions LxWxH: 9.0 x 6.5 x 6.5 meters
  • Material: mainly concrete


PTO specifications:

  • Reliable low-cost gearless PTO with asynchronous generator
  • Gearless Permanent Magnet (PM) DC Generator
  • Robust Gearbox and PM/asynchronous generator
  • Non-electrical PTO with hydraulic pumps
  • Energy loss of PTO: 10%-20%
  • Due to the large available dry space above the caisson other PTO's can be designed for various performances


Installation specifications:

  • Setup with the caisson serving as a barrier for creating water head 


Performance for applications with 2 meter water head:

  • Power output: 125 kW
  • Turbine CAPEX: 1,500 to 2,500 EUR/kWe
  • Indicative Opex (depending on the project scale and PTO): 5% of turbine CAPEX 
  • Typical indicative performance for application at existing dams with water ducts: CAPEX 2,500 to 3,500 EUR/kWe and LCOE 0.03 to 0.04 EUR/kWh


Performance for applications with 4 meter water head:

  • Power output: >250 kW
  • Turbine CAPEX: 1,000 to 1,500 EUR/kWe
  • Indicative Opex (depending on the project scale and PTO): 5% of turbine CAPEX 
  • Typical indicative performance for application at existing dams with water ducts: CAPEX 2,000 to 2,500 EUR/kWe and LCOE 0.02 to 0.03 EUR/kWh


Despite the fact that the turbine only Capex is a fixed low amount, many factors have influence on the total project Capex, Opex and the resulting LCOE. Primarily the scale of the hydro power plant, the water head and the capacity factors have a significant impact on the Capex and Opex.


If you would like to discuss some particular turbine application or the specifics of a potential hydro power site with the engineers of RONAMIC, please contact us via the contact form below.

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