Pareto frontier for multi-objective wind farm layout optimization balancing power production and turbine fatigue life

Layout optimization is a promising design process that will enhance the power efficiency of wind farms in the design stage. Single optimization targeting maximizing power production for wind farms has been studied for decades. Recently, multiple-objective layout optimization, considering more practical factors, has become urgently required with the rapid growth of wind energy. In this paper, we established a multiple-objective layout optimization framework that considers power performance and turbine fatigue life. Efficient power and fatigue life assessment approaches are adopted. Different scales of wind farms and typical wind roses are investigated. Pareto frontiers are drawn for each case to show the optimal solutions for multiple-objective optimizations. Notably, the deduction of wind speed and increase of turbulence intensity in the wake region have contrasting influences on the fatigue life. The turbines of optimal layouts are distant for higher overall power output but prefer to be closer for longer fatigue lives. Characteristic spacing describing the turbine density and the utilized area is suggested to be larger than 3.65D for any case and no less than 4.85D if the wind farm cannot afford the 85% power performance of the theoretical upper limit without wake loss.