At present time, wind energy is one of the most rapid developing electricity production fields worldwide. In 2014, total capacity of installed wind WT was 336,327 MW, out of which approximately 128,751 MW was installed in the EU countries [1] and [2]. In Lithuania, at the end of 2014, total capacity of installed WT comprised approximately 279 MW, and WT produced 6% of total electric power consumed in the country.
Wind power is now an undisputed pillar of electricity in many parts of the world. Wind energy installed worldwide can now contribute close to 5% of global electricity demand and significantly reduce CO2 emissions. Such fact must be evaluated, because in the last few centuries, the concentration of greenhouse gases (GHG) has been rising in the atmosphere. According to [1], [3] and [4], concentration of GHG is increasing due to increase in use of fossil fuels. The surface temperature has globally increased by 0.4–0.5 °C; the sea level has also risen at an average annual rate of 1–2 mm during this period [3] and [4]. Power sector is contributing 65% of the total CO2 emission [1]. It is evident that the WT generated energy significantly improves the environmental conditions.