The Concept

The Scotrenewables Tidal Turbine is an innovative floating tidal stream turbine designed for ease of installation, operations and maintenance, robustness and survivability in the harsh offshore environment. The device can be installed, transported or completely removed from the site requiring a small and readily available vessel.


The main structure comprises a floating cylindrical tube to which dual horizontal axis rotors are attached. The rotors extract the kinetic energy of the tidal flow, which is converted to electricity though the power take-off system for export to shore. The hydraulically retractable rotor legs give the tidal turbine two configurations - operational with the rotors down to generate power, or transport/ survivability mode with rotors retracted to decrease draught allowing the system to be towed into harbour or to reduce loads in heavy seas. In extreme storm conditions power generation will cease automatically and the rotor legs will retract up in to a transport /survivability mode. Additionally, the streamline design of the device ensures that any storm waves will pass smoothly over the system.

Some key benefits of the technical features include:

  • Floating design - enables turbines to be in region of typically highest tidal velocity (up to 50% higher energy availability compared to seabed mounted devices). All installation and maintenance operations can be undertaken using small low cost vessels.
  • Compliant Mooring System - enabling deployment in deep waters.
  • Passive Yaw System - improve energy conversion, simplify design.
  • Fixed Pitch Rotor Blades - to reduce design complexity and cost.
  • High performance, low mass - high power to weight ratio.
  • Survivability - automatic shutdown in storm conditions.
  • Accessibility - majority of maintenance can be carried out in water.
  • Rapid connection/disconnection - 30 minute operation to connect and disconnect.

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SR250 Operation Mode

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SR250 Transport/Survivability Mode