An Initial Study of Multimodality in Wind Farm Layout Optimization Problems

A study into the phenomena of multimodality in wind farm layout optimisation problems is presented. Little previous work has studied multimodality so this work aims to begin providing quantifiable results on multimodality in farm layout optimisation. The problems of optimising the location of a four and nine turbine farm within a bound circular domain are considered. Multi-start gradient-based optimisation is used to determine optima present in each case. Clear multimodality was found in all cases tested. With increasing farm size, the number of optima present increases, however the difference in performance of those optima is small. Therefore, while multimodality is present, for large farms, the chance of locating a local minima that has a detrimental performance compared to the global optimum, is small.