Methods for multiple floaters and dynamic cables at farm level

Floating wind farms is the next step in the global exploitation of offshore wind energy. In the initial demonstration projects, all turbines have been moored individually. For sites of large depth however, cost reductions may be achieved by utilization of shared mooring lines and shared anchors. This leads to additional dynamics at the farm level, since the turbines are now structurally connected. The aero-servo-hydro-elastic design tools therefore needs adaptation to these new configurations such that the new dynamic effects can be captured. This tool adaption is the focus of the present deliverable. The IEA 15MW [20] reference wind turbine with theWindCrete spar floater is used as the through-going example, with configurations both in the Gran Canaria and Morro Bay sites. The HAWC2 model of DTU [18] is used to investigate the shared mooring line designs which are evaluated in terms of mooring line forces, equilibrium states, frequencies and corresponding mode shapes. The site properties, designs and their results are given in the detailed study sections along with the parameters for the shared mooring line designs