On the wind speed reduction in the center of large clusters of wind turbines

The paper intends to probe the feasibility of a method to determine the wind speed reduction in the center of a large wind farm by means of simple boundary layer theory. Therefore, the simplest possible assumptions have been chosen.

The paper presents an approach for determination of the reduction of the wind speed assuming the wind turbines effectively act as roughness elements. The model makes use of similarities to so-called canopy flows, where the surface drag and the drag on individual obstacles are added to form the total drag. Results are compared with existing models for reduction of efficiency within wind turbine clusters and good agreement is found.