Poland, as a member of the European Union (EU), has to fulfill the obligations resulting from its membership in it. It is necessary to comply with numerous directives and other legal provisions adopted by the European Commission in the field of the energy market and production. Meeting the demands of the European Green Deal, as well as the solutions presented in the Fit for 55 package, is very difficult. In Poland, coal is still used in over 67% of electricity production. This article presents an attempt to join the multi-threaded discussion on renewable energy sources (RES) and the possibility of increasing their share in Poland’s energy mix. This article defines the RES support mechanisms in Poland, presents the support systems and instruments functioning within them, and also provides a statistical prediction of trends in energy production from RES for upcoming years. Research utilized the Brown, Holt, and Winters models and the cause-and-effect model. The research conducted in this article shows that Poland must make significant efforts to decarbonize the economy; in addition, the too quickly changing RES support system is not conducive to the development of these sources.