Turbine installation

Landowners: Turbine Installation

What is involved?
The installation of a wind farm takes no more than six months. The actual construction process is a series of distinct activities that can be planned in association with the landowner so as to minimise disruption to farming activities.  Once the turbines are in place, normal farming can go on around them. There is no requirement to fence off the towers and the rotating blades are well clear of the ground.

Tower Base
The turbines are built on concrete slab foundations. These slabs are around 14x14 metres (46 feet) by 2 metres (6.6 feet) deep. They are buried below normal ploughing depth, at least 1m below ground surface. Consequently, arable farming can continue right up to the base of the 4 metre (13-foot) diameter towers. The turbines are connected together by underground cables, which again are buried below ploughing depth, approximately 1m below ground surface. Cables can usually be routed along tracks or field boundaries to miminise disruption.

Roads
For access to the turbines, we require stone roads that are 5m (about 16 feet) wide. Like the cables, we can normally route the roads to follow existing tracks or field boundaries. Once built, the roads must remain in place for access to carry out maintenance or repairs and are available for farm use.

Operations
When the turbines are in operation, normal requirements for access are limited. Unless there is a (rare) major fault, maintenance will be undertaken from a small van every three months. The turbines are monitored remotely via a telephone line so there is no need for more frequent visits. The control systems in the turbines are fail safe, so if a fault does occur the turbines stop automatically and communicate with the operating company via the telephone line.

Turbine Details
Modern wind turbines typically have a hub height of 68 metres (223 feet) and a blade diameter of 62 metres (203 feet). When the blade passes its highest point, the tip will be at 99 metres (325 feet). At the lowest point, the tips are typically 37 metres (121 feet) in the air. For safety and turbine performance, it is necessary to have a separation between turbines equivalent to approximately 5 blade diameters, around 300 metres.

A small building in the order of 6 x 8 metres is required to house a meeting point for the cables from the individual turbines. This is called a switch gear house. From the switch gear house, a main cable will run underground to a local substation, hence there will be no new electricity pylons. Despite the number of turbines, only one switchgear house is required per windcluster.

Statistics

• Construction area: 1660m2
  (only during construction)
• Crane hard-standing: 80m2
• Turning circle: 256m2
• Accessway: 500m2 per 100m of road
• Switchgear house: 48m2

This means that less than 1 acre per turbine is lost for agricultural production, generally allowing 99% of windcluster site area to be utilised as it was previously.