The provision of energy resources is one of the main problems of the modern economy. As a result, energy security (stable supplies at affordable (rational) prices, stable functioning of international electric power markets, reduction of CO2 emissions) is an essential condition for economic growth and development, and concerns all post-Soviet countries. In recent decades, the volatility of electric power markets has increased with the emergence of new energy sources and the development of technologies, which leads to a change in the global structure of energy security. In such circumstances, the role of sub-regional electric power markets is increasing. It should be considered that the same sort of experience has already been applied: the Europe's Single Electricity Market, which has been developing over a rather long period and which has such characteristics as competitiveness and flexibility. However, despite the creation of the Agency for the Cooperation of Energy Regulators (ACER) in 2011, the single internal energy infrastructure of the EU has not been fully formed. In the EU countries, the creation of the market is aimed at improving energy security and energy efficiency by dividing the electricity business into two components - natural monopoly activities (transmission of electricity) and competitive activities (generation and selling of electricity). This has both political and economic significance, contributing to the strengthening of integration processes. However, due to some objective and subjective reasons, the Common Market of the Eurasian Economic Union was not created by the specified date (July 2019), so it is important to identify constraining factors and measures for its formation. © 2020 IEEE.