One of the most important problems of the Estonian energy system is the compensation of power fluctuations of wind parks. The possibilities of energy system stabilization by Estonian oil shale power plants are limited. At the same time the use of wind energy has not led to the expected reduction in oil shale consumption. Autonomous wind energy systems with some storage devices are one possible way to develop wind energy usage. A system consisting of a wind generator and storage device is analyzed in this article. The storage device might be a fuel cell with hydrogen storage, pumped storage, flywheel or battery. A unit generator and the normalized and averaged power curve of small wind turbine generators are used for the analysis of wind data. Average hourly wind speeds are measured in different locations of Estonia. The duration, frequency and distribution of windless time periods are analyzed. The estimated principles of storage device selection are given according to wind data and power curves.