The paper sets out the methodology and made net energy and exergy analysis of the low-speed multiblade windmill WEI-5-4, the coefficients of net energy and net exergy, energy and exergy payback periods produced for the conditions of a number of regions of the Russian Federation. Calculations made in the article indicate a high exergetic efficiency of wind power plants due to the fact that the end product of their production is electricity, while the creation of such systems spent a lot of heat.