The bottom circular mounting flange with bolt-holes on the base is used to fit the tower foundations.
A large area is excavated to accept over 1000T of poured concrete foundations. These have a ring of long steel high tensile foundation bolts set into the concrete before it dries.
The tower is lowered onto founds and once the flange boltholes are aligned with the ring of bolts, dropped into position and leveled.
The large flat washers are fitted over the bolts and the nuts screwed on and hydraulically torqued, to ensure the highest strength attachment. These steel reinforced concrete foundations and high-tension bolting support and secure the combined weight of a large capacity unit weighing upwards of 160 tons.
The nacelle is slung horizontally using web slings and wire strops and lifted onto position on the top of the tower. It is fitted to the tower using the mounting flanges then the yaw mechanism is installed.
Hub and Blades
Depending on the weight these two components can be installed on the ground and lifted into position. The hydraulics, electrics and shaft couplings are then installed.
The Wind Farm Location
Wind speed, direction, and continuity data is recorded for some time before selecting the site for the wind farm, normally on a hill or a ridge, with a good continuous wind supply of between 5 and 15 m/s.
It must be remembered that although the area taken up by a turbine is not that great, they must be positioned so that they do not shelter the wind from each other which means the total area of the wind farm for, say, thirty turbines can be great amounting to 50 acres/MW of output power capacity
The components of the turbine and the crane and diggers plant are all large, so roads to the area may have to be widened and straightened with new roads constructed right up to the selected site.
A boundary safety fence will be built around the site and along new access roads, usually to the delight of local farmers.