Sway concept explained on CNBC and Fox Business Network
The SWAY® system is a floating spar wind turbine for offshore locations in 60 – 300m+ water depths. The general continuous spar type floating tower concept is exclusively patented by Sway worldwide both for tension leg moorings and slack moorings.
The floating tower is anchored to the seabed with a tension-torsion leg which is equipped with a passive subsea yaw swivel. I.e. the entire tower yaws together with the turbine when the wind changes direction. The yaw motions are entirely controlled by individual pitching of the rotor blades, including in “no wind” conditions where the rotor can still be rotated by running the generator in motoring mode.
The tension leg and subsea swivel are based on well proven concepts and materials used by the offshore oil and gas industry for many years.
The anchor system is generally a major cost factor for all the current floating wind turbine foundations concepts. The Sway patented single leg anchor system saves more than 60-70% of the anchoring costs compared to the slack mooing systems.
Using a downwind turbine the tower is supported by a patented tension rod system, similar to a sailboat mast, reducing the tower steel weight by almost 50%.
The feasibility of the system has been verified through extensive dynamic simulations over the last 8 years and by a prototype installed in Norway.
System dynamic behaviour, fatigue life and extreme loading conditions have been well documented.
Due to its low steel weight and minimalistic anchoring system the total Sway tower/foundation and anchoring costs is estimated to be less than 50% of the costs of the most promising competing floating foundation systems and is comparable to the costs of jacket foundations in shallow (30m) water.