The construction for wind projects generally takes 8 to 18 months, depending on the project size and seasonal conditions. Generally, the first few months are the most active with cranes, trucks and work crews on-site as the turbine foundations are prepared and turbine components are delivered.
Access Roads
Each wind turbine site begins with building construction access roads to connect the turbine sites. After the wind turbines are installed, the construction access roads are converted to permanent gravel access roads that are about 16 feet wide.
Wind Turbine Foundations
Typically, the foundation for each wind turbine consists of a concrete spread footing that is buried 8-12 feet underground, depending on soil conditions, and with a 4-6 foot tall cylindrical pedestal that is exposed 6-10 inches above finish grade with a 10-15 foot gravel (“beauty”) ring around it. Post construction, farming and grazing activities can resume within 15 feet of the pedestal.
Wind Turbine Construction
Wind turbines are composed of a tall tower, a 3-blade rotor, and a nacelle which houses all the gears, generators and electrical conversion equipment. All the components are delivered and laid out on temporary crane pad and assembly areas adjacent to the wind turbine foundations. Assembly begins by bolting the tower base section to the foundation pedestal and then bolting the remaining tower sections into position, followed by erecting the nacelle and the rotor using a very large tall crane. Each turbine takes about 4 to 5 days to erect from offload to pre-assembly and effective staging of components.
Electrical Collection System and Project Substation
An underground electrical collection system connects each wind turbine and carries the electricity generated by each wind turbine to the to the project substation. In most cases, an overhead transmission line is also installed connecting the project substation to the electrical grid interconnection facility or point of interconnection (POI).
O&M Building
Most projects will construct a 5,000 square foot operations and maintenance building to house the onsite staff, the equipment, and spare parts necessary for ongoing maintenance of the project.
Commercial Operation
Once all the wind turbines are fully operational and capable of producing power into the energy grid, the construction phase is deemed complete and the project will be commissioned. After commissioning is complete, the project will be handed over to the operations and maintenance crew.