According to their website, the ScotRenewables tidal turbine (SRTT) system is a free-floating rotor-based tidal-current energy converter that began development from a PhD project in 2004 (ScotRenewables, 2008). The design has won various awards, including an Enterprise Fellowship – awarded by the Royal Society of Edinburgh and Scottish Enterprise.
The concept in its present configuration involves dual counter-rotating horizontal – axis rotors driving generators within subsurface nacelles, each suspended from separate keel and rotor arm sections attached to a single surface-piercing cylindrical buoyancy tube (Figure 4.23 (right)). The device is then anchored to the seabed via a yoke arrangement and compliant mooring system. A separate flexible power and control umbilical then connects to a subsea junction box. The rotor arm sections are hinged to allow each two-bladed rotor to be retracted so as to be parallel with the longitudinal axis of the buoyancy tube, giving the system a transport draught of under 4.5 m at full scale to facilitate towing the device into harbours for major maintenance.
No power data are presently available for the ScotRenewables tidal turbine.
