Floating, yawing spar current/tidal turbine

Abstract

The present invention describes a floating yawing spar buoy current/tidal turbine. The spar includes a spreader above the rotor(s) with the spreader tips connected to fore and aft cable yokes that transition to opposing mooring lines connected to anchors on the seabed. The spreader comprises a yaw motor, which drives gears that engage with a ring gear fixed to the outer perimeter of the spar. Flow direction sensors activate the yaw motor for automatic yaw adjustments of the spar turbine. As tidal direction changes, the entire spar and turbine are yawed to maintain the rotor plane facing the tidal flow. The bottom end of the spar extends to approximately the bottom sweep of the rotor plane and contains a winched vertical mooring line, extending to the seabed and attached to a gravity or suction pile anchor. The turbine drive train can be accessed for servicing from the surface via hatches and ladders within the spar to enter the drive train and generating system vessel. The spar turbine is deployed by towing it in a horizontal position. At the operating site, the yokes are connected to the forward and aft mooring lines and the winch line is connected to the gravity anchor. The winch inside the keel draws the bottom end of the spar down and may be assisted by flooding the keel to reach a vertical position for the spar. The winch is then locked to retain required operating depth, or can actively control operating depth in areas of wide tide level range.