The paper discusses the impact of independent power stations connected in the distribution networks on the normal operation of these networks and their performance parameters: voltage losses, power flows and overloads, annual energy losses, etc. As objects of the research, independent power stations were taken: hydroelectric, wind and cogeneration power stations of the Western Electrical Network of Latvian Power System. Four objects were analysed: 1) three HESs connected to the 20 kV network; 2) four HESs connected to the 20 kV network; 3) two cogeneration electric stations and two wind power plants connected to the 110 kV network; 4) 33 wind generators connected to the 20 kV network. The analysis has shown that · the capacity of independent electric stations should be reserved in the energy system; · the first and the fourth objects increase electricity losses in the distribution network; · the second and the third object decrease electricity losses in the distribution network; · the impact of independent electric stations on the distribution network is determined by the load-generation balance. The results of the research would be interesting not only for the Western Electrical Networks, but they also are of general importance outside Latvia. The obtained results will help in solving many problems.