Validating Model Simulations using Wind Lidar Profiles over the Maryland Offshore Wind Energy Area

One of the most challenging aspects of carrying out an offshore wind resource assessment in the U.S. Midatlantic region is the lack of long-term hub-height wind observations within designated wind energy sites. Therefore, modeling studies must be used in lieu of direct observation records to help better characterize the offshore wind resource. However, simulation results alone are not considered bankable since weather prediction models are imperfect and frequently do not capture the fine-scale wind characteristics that are actually observed. Furthermore, regional models are sensitive to their configuration, physics, and selection of meteorological input for initialization and boundary conditions. Therefore, it is very important to carefully validate simulation results in order to establish a baseline for model integrity in the immediate Midatlantic region where offshore in-situ observations remain scarce.

During the summer of 2013, the University of Maryland Baltimore County (UMBC) placed several meteorological instruments onboard a ship that traversed the offshore Maryland Wind Energy Area (MD WEA). This campaign provided wind lidar measurements which captured profiles up through turbine heights. The resulting measurements, combined with existing observation sources, provided a validation dataset for developing high-resolution model configurations that best reproduce the wind patterns observed in the MD WEA.

This research highlights case studies showing model-observation comparisons and results from model sensitivity tests conducted using the Weather Research and Forecasting (WRF) model. Sensitivity tests investigated the impact of (1) increasing spatial and vertical resolution, (2) using different operational, reanalysis, and satellite meteorological input, and (3) testing the representativeness of several boundary layer parameterizations. Case studies that were of particular interest to wind energy included sea breeze and low-level jet events, which can impact turbine height winds. This research reveals what simulations produced the best results compared to the observed lidar wind profiles in the MD WEA.