A new concept for a floating wind turbine platform that aligns itself depending on wind conditions is being developed in Germany under the framework of the joint research project HyStOH, set up by the Federal Ministry for Economic Affairs and Energy (BMWi).
The Hamburg University of Technology (TUHH) has investigated and optimised the concept for the self-aligning floating wind turbine platform, with the investigations carried out in cooperation with scientific and industrial partners.
The SelfAligner concept is based on a passive wind tracking system and a turret buoy anchoring, allowing for the entire platform to rotate freely around the mooring point. In addition to the rotor, an airfoil-shaped tower provides the necessary forces for the alignment.
“The nacelle of the wind turbine is mounted directly on the tower since no yaw bearing is required to turn the rotor. The rotor is arranged downwind behind the tower. Due to the aerodynamic shape of the tower, its wind wake is reduced, which has a positive effect on the dynamic load on the rotor blades. Thus, the blades experience a significantly lower impact load as they pass the tower”, TUHH explained.
The platform’s semi-submersible structure can be installed in water depths of beyond 40 metres, and its passive wind aligning is made possible through profiled tower and downwind rotor configuration.
The platform’s lightweight construction can be produced at conventional shipyards without modifications to production facilities, making this concept cost-effective, according to TUHH, which also highlighted its easy installation and removal due to detachable single-point mooring, as well the SelfAligner’s reduced environmental impact.
The project partners include CRUSE Offshore, the TUHH with the Institute for Fluid Dynamics and Ship Theory and the Institute for Ship Structural Design and Analysis, DNV GL, aerodyn, and Jörss-Blunck-Ordemann.
For the investigations and optimisation, the project partners used resources such as the panMARE method from the Institute for Fluid Dynamics and Ship Theory, as well as a 1:45 scale model of the platform in a wave tank.