Design of reference floating offshore wind farms in three areas

Design optimization of bottom-fixed offshore wind farms has been a quite mature endeavour [1], while relatively few studies have been done for the design optimization of floating offshore wind farms (FOWFs). Comparing to their bottom-fixed counterparts, FOWFs face special challenges brought by the movement of the floating platforms, which may bring some non-negligible effects on the wake flow and power production for the FOWFs. Among the limited literatures dealing with the design optimization of FOWFs, most of them either ignore the movements of the floater or only consider part of the movements [2]. A recent study lead by DTU [3] has also included the steady state motion of floating offshore wind turbines (FOWTs) in the FOWF modelling and proposed a method to optimize the design of FOWFs. As this method relies on a turbine surrogate model built on a large number of aero-elastic simulations of FOWT under different met ocean conditions, we need to have the complete design of the FOWT and its aero-elastic model first before using it.
However, in the planning phase, decisions like where to build the FOWF need to be made while the detailed design of the FOWT has not been finalized yet. Assuming the capacity of the FOWT and the total capacity of the FOWF are specified, we will need to obtain preliminary layout designs of the FOWF. In this process, the effects brought by movements of platform can be ignored, as firstly we don’t have the detailed design yet, and secondly the impacts on the annual energy production (AEP) are usually quite small as shown in [3]. Thus, we propose a method to design reference FOWFs for a given area and applied it to three areas: the Scottish Sea, Baltic Sea and Adriatic Sea. This method is based on static layout optimization which treats turbines as bottom-fixed ones.