A Comparative Cost Analysis of Floating Wind Turbine Platforms Available to Purchase

This thesis presents a cost-of-energy (COE) analysis comparing three types of floating wind turbine platforms—spar-buoy, semi-submersible, and tension-leg platform (TLP)— based on existing commercial designs. The analysis develops the COE of a 500-MW reference wind plant at a reference offshore location using a merit-based criterion that integrates both lifecycle cost and turbine energy production. A sensitivity study examines how fluctuations in site-dependent operating parameters and fabrication cost factors affect results. The analysis demonstrates that while the COE of a floating wind plant can vary across a wide range ($0.10 to $0.22/kWh), the relative COE performance of the three platforms does not change. The TLP consistently enables the lowest COE across a range of operating parameters as a result of its comparatively low steel weight and less expensive mooring and anchoring system. The percent differences between the COE enabled by the TLP and that of the spar-buoy and semi-submersible are 4% and 19%, respectively, at the baseline reference site.