Draft PPS 18: Renewable Energy
Annex 1 Wind Energy: Other Infrastructure
A18. In addition to wind turbines, the required infrastructure of a wind farm consists of adequate road access, on site-tracks, turbine foundations, crane hard standings, one or more anemometer masts, a construction compound, electrical cabling and an electrical sub-station and control building. Some of these features are permanent and others are required only in the construction phase and as such are temporary.
A19. One or more anemometer masts may be required on-site. These are usually slender structures with guy supports, built to the hub height of the turbines, with anemometers and wind vanes mounted at different heights. Anemometer masts are needed as part of the project planning and design process but they are also needed post-construction in order to provide control information.
A20. A construction compound will generally be specified in the proposal. While this is of a temporary nature, its location should be identified with the planning application.
A21. The road access to a wind farm site will need to be able to accommodate trailers carrying the longest loads (usually the blades), as well as the heaviest and widest loads (generally the cranes required in erection). Amendments to existing roads required to gain access to site should be detailed in any wind farm planning application.
A22. On-site tracks need to meet the weight and dimensional requirements detailed above. A developer may propose that they are left in this condition for the life of the wind farm or may ask to retain them in a reduced state (by, for instance, narrowing the roads and reinstating the verges). In either case there will be an operational requirement for decommissioning and to gain access to the site for routine maintenance with light vehicles, as well as to reach the site with loads potentially as large as those initially used. This would only be required in the case of a major component failure.
A23. Larger hard standings are also required next to each turbine to act as bases for cranes during turbine erection and component lay down areas. These hard standing should be constructed and finished in an appropriate material to allow for habitat regeneration.
A24. The towers of the turbines are fixed to a concrete foundation whose surface will normally be flush with the surrounding ground. This foundation pad is likely to be square or hexagonal in shape and about 7-20 metres across. The diameter of the base of the turbine tower is likely to be 2-5 metres. The land area actually used by the turbines is therefore very small. On land where public access is allowed, people might walk right up to the base of the towers without interfering with turbine operation. On land normally used for agricultural purposes, agricultural use could continue right up to the edge of the foundations.