Potential of load and O&M costs reductions of Multi Rotor System for the south Baltic Sea

Abstract. Many coastal regions in Norway, Spain, Portugal, Japan or the United States are comprised of large water depths (> 50 m) making the installation of typical bottom-fixed off-shore wind turbines very difficult and expensive. This is the reason why the floating wind turbines (FOWT) are a promising solution able to exploit the high energy potential contained in these regions. The Advanced Multi-Rotor Turbine for Deep Water Off-shore Energy (AMRowe) has been undertaken to design and develop a cost–competitive, innovative floating Polish multi rotor system, aiming at the optimal usage of European off-shore wind potential. In the article, a prospective deep off-shore location in the south Baltic Sea is identified. The authors built a cost model to prove its superiority over the sites already commissioned by the Polish government. A set of metocean conditions tallied for a 50-year period is used to assess performance of the proposed multi rotor floating wind turbine and to benchmark it against a single rotor 5 MW baseline turbine. The typical load cases are also investigated to observe impact on a single rotor blade in an multi-rotor arrangement in order to begin search for the key design drivers.