Draft PPS 18: Renewable Energy

Annex 1 Wind Energy: Spacing of Turbines

A16. Wind turbines need to be positioned so that the distances between them are between 3-10 rotor diameters (about 180-600 metres for a wind farm using 60m diameter, 1.3MW wind turbines) depending on the individual circumstances of the site. This spacing represents a compromise between compactness, which minimises capital cost, and the need for adequate separations to lessen energy loss through wind shadowing from upstream machines. The required spacing will often be dependent on the prevailing wind direction as illustrated in Figure 3 below, which shows a possible layout for a site in Northern Ireland with a typical South Westerly prevailing wind direction.

Figure 3

Example turbine spacing in a wind farm with a South Westerly prevailing wind direction

A17. Bearing in mind the requirements for optimal performance, a distance of not less than two rotor diameters from adjoining property boundaries will generally be expected, unless there is written agreement of adjoining landowners to a lesser distance.