As we saw in the previous section on the wake effect , each wind turbine will slow down the wind behind it as it pulls energy out of the wind and converts it to electricity.
Ideally, we would therefore like to space turbines as far apart as possible in the prevailing wind direction. On the other hand, land use and the cost of connecting wind turbines to the electrical grid would tell us to space them closer together.
As a rule of thumb, turbines in wind parks are usually spaced somewhere between 5 and 9 rotor diameters apart in the prevailing wind direction, and between 3 and 5 diameters apart in the direction perpendicular to the prevailing winds.
In this picture we have placed three rows of five turbines each in a fairly typical pattern.
The turbines (the white dots) are placed 7 diameters apart in the prevailing wind direction, and 4 diameters apart in the direction perpendicular to the prevailing winds.
Energy Loss from the Park Effect
With knowledge of the wind turbine rotor, the wind rose , the Weibull distribution and the roughness in the different directions manufacturers or developers can calculate the energy loss due to wind turbines shading one another.
Typically, the energy loss will be somewhere around 5 per cent.
© Copyright 1997-2003 Danish Wind Industry Association
Updated 1 June 2003