The paper presents the results of a study and analysis of the structure of the balances of installed capacity and electricity generation at power plants of the energy interconnection of the CIS and Baltic countries. Based on an analytical study of the structure of power and electricity balances, the dependence of the cost of electricity on the structure of electricity generation at power plants of various types is shown. The lowest cost of electricity is found in Georgia, Tajikistan and Kyrgyzstan, where more than 80% of electricity is generated annually by hydroelectric power plants.