Manufacturing and assembly of the main components of a wind power facility take place in the factories of the suppliers, and the following components are typically then shipped to site:
• foundation anchors or tubes
• three to four tubular tower sections
• ground controller and switchgear
• fully assembled nacelle
• hub and blades
• wind farm Supervisory Control and Data Acquisition system (SCADA)
• pad-mount transformers
While awaiting shipment of wind turbines from the factory, the following site preparation begins: civil engineering, including access roads, turbine foundations, substation, and electrical infrastructure.
Wind turbines are large and heavy so suitable site access for transport is required. Heavy lifting equipment is used on site. A crane is used for hoisting the tower sections, nacelle and rotor into position. The assembled nacelle typically includes several components: the turbine bedplate, gearbox, generators, yaw mechanism, mainshaft, converter and sometimes the transformer.
Once the turbines are installed, all cabling is terminated, hardware is torqued, the turbine is commissioned, and a connection is made to the electric utility grid.
From the time the materials are delivered to the site to the date of commercial operations ranges from 6 to 9 months for a typical U.S. project.