Loads Analysis of Several Offshore Floating Wind Turbine Concepts

This work presents a comprehensive dynamic-response analysis of six offshore floating wind turbine concepts. Each of the six models contained the same 5-megawatt (MW) turbine. The platforms modeled included: a barge, a semisubmersible, two tension-leg platforms (TLP), and a spar buoy at two different depths. The performance of these models was compared to that of a base model with a turbine supported by a fixed land-based tower. Performance was evaluated via a comprehensive loads and stability analysis adhering to the procedures of the International Electrotechnical Commission (IEC) 61400-3 offshore wind turbine design standard. The loads in the turbine supported by the barge are the highest found for the floating concepts. The differences in the loads between the TLP, the semisubmersible, and the spar buoy are not significant, except for the loads in the tower, which are greater in the spar and semisubmersible systems. The results of this analysis will help resolve the fundamental design trade-offs between the floating-system concepts.