For the design of wind turbines it is necessary to consider several conditions such as: wind, turbulence, temperature variations, geology and characteristics of foundation soils on site, earthquake and neighborhood restrictions. The selection of the types and dimensions of the wind turbines foundations are dependent on the geotechnical conditions, the maximum power of turbines and the type of tower. This paper presents various tower structures correlated with the corresponding types of foundations currently used for wind turbines. For this research, the authors performed a variety of analyses and studies involving different characteristics of the locations for the wind turbines. The research shows the solutions obtained for the pile foundations and their impact upon the environment. The paper points out the influence of the pile length on the slope stability as resulted for the soil stratification from the investigated locations.