Tension Leg Wind Turbine (TLWT) Conceptual Design Suitable for a Wide Range of Water Depths

摘要

Wind turbine technology has developed tremendously in the lastdecade resulting in the installation of large turbines with rated powergeneration of more than 5 MW. Such units with hub heights of morethan 90 m and the rotor diameter of more 120 m or more require carefulstudy of support structures. Bottom-supported structures can bedesigned cost effectively in relatively shallow water but the costeconomics can be challenging at water depths of about 50 m inrelatively harsh environments. This paper describes conceptual designof a positively buoyant Tension Leg Wind Turbine (TLWT) facilitysuitable for both moderate and deep water. It is competitive withbottom-supported structures in moderate water depths of 40 to 50 mbased on both fabrication and installation costs. The added advantageof the TLWT design is that floating structure design is largelyunaffected by the water depth. The design incorporates adequatepositive buoyancy so that only the magnitude of ballast is modified toaccount for the weight of tether lengths at different water depths.In addition to the description of the design, wind turbine characteristicsincorporated into design, description of design details, fabrication andinstallation options as well as applied ocean environment loadsaffecting the design of tethering system and the overall fabricated andinstalled costs are presented for both 50 and 100 m water depth sites.