Investigation of wake interactions effect on wind farm efficiency

Abstract

Seeking for an optimal location of wind turbine systems with the aim to minimize the aerodynamic interactions between them and maximize the output power is one of the most complex problems in the stage of wind farm design. In general the wake interferences created by upstream systems influence the quality of power produced by downstream turbines. In this spirit, this paper presents an optimization approach in preliminary design phase that looks for an optimal location of wind turbines that extremize the power generated with low active power losses due to wake effect. Therefore an area with nine similar wind turbines (3 lines and 3 columns) is proposed as a case study. The power losses are quantified using a standard analytical wake model. The optimal arrangement is based on criteria (total power produced and wind velocity deficit) as a function of crucial design variables (inter-space between turbines and rows). Results and discussions show that power production is significantly decreases when turbines operate in low distance where wake interactions level is very important. This degradation can be avoided if downstream turbines are displaced from upstream ones. In addition this study proves that the important effect of low variation of wind direction can be reduced if perpendicular space is large.