Mesoscale modeling and remote sensing for wind energy applications

Wind resource assessment for wind energy applications increasingly relies on advanced wind flow modeling approaches based on Numerical Weather Prediction (NWP) tools and remote sensing techniques such as Sonic Detection and Ranging (SODAR) for early inspection studies. While NWP Modeling at least in principle allows for an early wind resource assessment without on-site data, SODAR is a convenient tool for the exploration of The wind resource at varying site locations at an early stage of the project development process. In the present work the output of reanalysis and operational weather models such NARR (North American Regional Reanalysis) and NAM (North American Mesoscale model), respectively, has been validated against Selected automatic surface observation stations (ASOS), and WRF-ARW (Weather Research and Forecasting - Advanced Research WRF) has been used for the generation of high-resolution regional wind speed maps through dynamical downscaling procedures. Using downscaled regional maps for 30 m height the potential for rural electrification with small wind turbines at communities with a particularly low Human Development Index (EMI) has been evaluated. A SODAR unit located at a complex location was first calibrated against concurrent anemometry measurements at a tall tower and then used for an exploration of wind flow and boundary layer physics during a 15-month campaign. Atmospheric stability was assessed through the analysis of the vertical wind direction fluctuations. The friction velocity under different stability conditions was extracted from profile plots and derived parameters such as the planetary boundary layer height and the friction drag were analyzed. While the general agreement of the observed profile plots with the predictions of boundary layer theory is fair, deviations particularly at lower measurement heights have been found which can be attributed to topographic effects.