Wind energy is an increasingly important factor of the power system in Europe. But it is still just a small part of the significant changes of the new millennium, namely the spreading of micro power and decentralisation of the whole energy system which are very important elements of sustainability. This paper shows the importance of wind power from the environmental point of view. In addition, it highlights the difficulties of understanding this topic which comes from its complexity. During teaching procedures geography teachers can show the connections between economical, technical and ecological phenomena in the different fields of geography. This kind of complex approach is crucial in research and teaching as well in order to understand the changes and contribute to sustainable development. (Contains 4 tables, 1 figure and 2 notes.)