A new offshore wind farm system that promises faster, cheaper installation and operations will be tested in the Mediterranean. Called the NextFloat+ Project, it received a €13.4-million (US$14.4-million) grant from the European Commission.
Setting up wind farms at sea seems like a logical idea. Sea breezes tend to blow regularly and open water provides a more predictable and dependable wind pattern than on land. Plus you don't have to worry so much about compulsory purchase of the building site.
However, the engineering challenges of setting up turbines at sea are so great that they often outweigh the benefits. This is because not only do the turbines need to be very robust, with blades that won't bend under load and strike their own mast, they also require heavy mooring systems to keep them in place that are expensive to install.
NextFloat+ is a consortium led by Barcelona-based X1 Wind and includes Technip Energies and NextFloat Plus SAS. Its purpose is to build a prototype 6-MW wind station called X90. This is a triangular floating platform with a single turbine that is assembled onshore and then towed to the installation site.
The X90 uses Single Point Mooring (SPM) and a Tension Leg Platform (TLP) system that doesn't require special heavy equipment to install. In a TLP, the triangular structure floats on the surface and three cables connect to a mooring on the seabed at depths of over 1,600 ft (500 m). These are then tensioned to keep the platform precisely in place. For the X90, the TLP uses a SPM to the cable trio that allows the platform to passively turn into the wind. Before the platform is floated out, the SPM is installed with a quick-connect system that lets the platform be snapped into place on arrival.
