The paper presents key economic and regulatory conditions of the further consolidation of the domestic power sector. The most important consequences of the implementation of governmental strategies and policies, which formed the current organizational structure of the Polish energy sector, were analysed. Furthermore the key objectives of European energy policy, which include the development of the internal energy market, were discussed. It was emphasized that the implementation of projects of common interest (PCI) is of utmost importance for the creation of the internal European energy market. A direct consequence of the introduction of EU energy policy will be an increase in the level of transmission capacity between Poland and adjacent countries from the current level of less than 5% to around 10–15% (the level that is currently available in countries such as Germany). The analysis carried out in this paper confirms that with increasing cross-border electricity trade, there will be strong pressure on domestic electricity prices and, consequently, Polish power companies will have to compete with other European power enterprises. The actual integration of the Polish energy market, at least at the level of regional markets, is therefore a matter of time. In this context, the paper concludes that the proper preparation of Polish companies to compete with European energy companies is required and that their further consolidation needs to be considered.