Assessment of Onshore Wind Farm Performance to Geometric Layout Choices by Utilizing Mesoscale Modelling Techniques

Abstract

Previous studies have shown that the average losses of wind power production due to the wind turbine wake effect within operating wind farms is between 10% to 20% of the overall power output. Among other factors, it is reviled that, the wind farm array layout can contribute significantly to both wake effect and power loss at the wind farm site. This study employs mesoscale modelling techniques to assess the effect of geometric layout on the onshore wind farms performance. Geometric layout can be defined by the spacing and alignment (e.g. staggered or aligned) of the wind turbines with respect to the prevailing wind direction. The Weather Research and Forecasting (WRF) model in this study utilised Fitch’s wind farm parameterization to simulate the interaction between wind turbine blades rotation and the atmosphere. To examine a wide range of operating conditions observed within the real-world operating wind farms, two idealised numerical simulations are carried out for each designed wind farm geometric layout, one with the convective condition and another with stable condition. Among the four different designed wind farm geometric layouts, the triangular wind farm layout which offered staggering after every next row was noted to be the easiest method for improving the wind farm performance by increasing the capacity factor from 0.55 to 0.71 and decreasing array losses from 9.15 % to 4.63 %. Comparison between stable and convective regime indicates that the highest capacity factor was obtained during the stable case with the highest power loss owing to increased wake impacts downstream. The lowest value of the capacity factor was obtained during the convective case with the lowest power loss for both four designed wind farms.