An Optimized Universal Spread Mooring System for Utility Scale Floating Offshore Wind Farms

Abstract Floating offshore wind turbines are a nascent technology with demonstrated potential of harnessing the substantial prevailing wind energy in water depths beyond the commercial limits of fixed offshore wind farms. While the latter are competitive with conventional sources of electrical energy generation, the floating wind industry is challenged to reduce the current estimated Levelized Cost of Energy (LCOE) by 50-70% to justify sanctioning of utility scale floating wind farms and unlock the full potential of offshore wind energy. Several studies have estimated that the capital and operating cost of the spread mooring system is about 15% of the total cost of a floating offshore wind farm. Mooring systems of the limited number of semisubmersible, spar and barge demonstrator, pilot and pre-commercial wind farms installed to date were not designed for optimally or scalability. This paper presents the design of an optimal spread mooring system that will dramatically reduce the total installed cost (and LCOE) of utility scale floating wind farms. The proposed system will: Utilize proven or qualified components that will be applicable for a broad bandwidth of wind farm water depths (70m to 1,000+m) irrespective of floating wind turbine foundation typologyBe installable in a wide range of soil conditions ranging from soft clays to stiff sandsHave a supply chain that can meet the demands of supplying, installing and maintaining mooring systems for multiple utility scale wind farms