The condition of the Polish energy sector does not inspire any trust of its customers. Outdated machinery and the lack of investment in new technologies make it necessary to take action to ensure the stability and continuity of electricity supplies to the end-user. In Poland, the industrial power sector is based on the use of coal and despite the Government’s announcements to resign from this raw material, more and more power investments are being made to generate energy from coal (Ostrołęka power plant). The solution which compensates for the current state of the Polish power industry is the development of distributed generation. The article presents a description of dispersed sources, power market, its organization and problems arising from its implementation. Distributed energy sources in the form of micro installations, energy clusters and virtual power plants have been described and characterized as well. It also assesses the impact of power market introduction on the development of distributed energy sources. The impact of the power market on the development of distributed sources is very hard to predict and determine. The functioning and further development of the energy sector, including the capacity market, strongly depends on the laws, regulations, as well as the economic and political situation in Poland and Europe. The social factor will also play an important role as the introduction of the capacity market will burden the financial side of each energy consumer. On the basis of the data presented on particular sources and distributed systems, one can only make predictions related to the possible effects of introducing the capacity market for the development of distributed sources.