Mobile modular platforms and method for near-shore assembly of floating offshore wind turbines

A method for assembly of a floating offshore wind turbine, comprising:

• a modular floating hull assembly platform having a first crane module with a first crane and at least one work module, wherein each of the modules having a rectangular hull with a flat top deck above a waterline;
• a plurality of floating hull components stored temporarily on the work modules of the floating hull assembly platform;
• a modular floating mat providing a dry area above the waterline for assembling the floating platform hull components;
• a modular wind turbine assembly platform having a second crane module with a second crane and at least one work module, wherein each of the modules having a rectangular hull with a flat top deck above the waterline;
• a plurality of wind turbine components including tower sections, nacelles and rotor blades stored temporarily on the work modules of the wind turbine assembly platform;
• a plurality of module legs each having an upper part and a lower part;
• a pulling system comprising a plurality of wires, posts with sheaves guiding the wires, and winches for pulling the wires;
• a modular floating wind assembly base comprising the modular floating hull assembly platform and the modular wind turbine assembly platform arranged in an end-to-end configuration, wherein each of the crane modules and work modules is supported by four module legs, wherein each leg having an upper part rigidly connected to the rectangular hull of each of the modules and a lower part firmly embedded below a seafloor;
• a temporary floating configuration wherein each of the crane modules and work modules of the floating wind assembly base having the module legs retracted upwards with the upper part rigidly connected to the rectangular hull of each of the modules and the lower part retracted to a bottom of the rectangular hull of the module above the seafloor, and
• the method further comprising:
• Step I, deploying a modular floating hull assembly platform comprising the first crane module with the first crane and two work modules, wherein the first crane module is arranged in the middle between the two work modules in an end-to-end configuration at a near-shore site located at a distance between 200 and 2000 meters from the shoreline in a water depth ranging from 5 to 15 meters, wherein a long side of the floating hull assembly platform faces the shoreline, wherein the first crane module and the two work modules are supported by the module legs each having the upper part rigidly connected to the rectangular hull of each of the modules and the lower part firmly embedded below the seafloor.