Wind structure during mid-latitude storms and its application in Wind Energy

This study investigates the offshore atmospheric characteristics during storm conditions through measurements and numerical modeling. The atmospheric characteristics are described through a number of key parameters that are relevant for coastal offshore wind energy and engineering application: the mean wind and turbulence structures, as well as gust.
This study aims at improving the understanding and modeling for the challenging wind and wave conditions during storms in the coastal offshore zones where a large number of wind farms are being planned in the near future in Europe, especially in Denmark. The extreme wind and wave conditions in the coastal area for wind energy application are important but have rarely been studied in the literature.
Our experiments are done to the Danish coasts where the mid-latitude depression systems are causes of the extreme wind and wave conditions. The numerical modeling is done through an atmosphere-wave coupled system, where the atmospheric model is the Weather Research and Forecasting (WRF) model and the wave model is the Simulating WAves Nearshore (SWAN) model. Measurements from offshore stations, Horns Rev and the FINO platform, as well as satellite wind imagines are used jointly with the numerical modeling. The point measurements include mean meteorological parameters such as profiles of wind speed and direction, turbulence and integrated wave parameters.
The behaviors of the “key” wind and wave parameters from both the measurements and the modeling will be presented. Here the “key” is referring both to the application of wind energy and the wind-wave coupling system. The various parameterization of the interface parameter for the atmospheric and wave modeling, the roughness length, has been examined. Data analysis reveals the importance of model setups (domain, initial time and resolution) and input data (large scale atmospheric forcing and bathymetry data). The wind structures were both examined for open sea and fetch limited conditions.