In the past, wind data were measured and evaluated almost exclusively from a meteorological point of view. However, these older data are insufficient with regard to the technical use of wind by wind turbines. The information about the properties of the wind at heights up to 150 m, especially about the increase in wind speed with altitude, or the local wind conditions of a particular terrain are limited. Comprehensive wind measurements have only been carried out for around thirty years, considering the special aspects of the use of wind energy. In the meantime, full-coverage wind data are available in the countries where wind energy utilisation is widespread. Furthermore, the long-term evaluation of the energy supply of existing wind turbines forms a reliable database