This paper discusses the challenge of reconciling the different values present in European Union policy, with a particular focus on the key regulatory aspects of the new directive on the promotion of energy from renewable sources (the RED III Directive). Particular attention was paid to the provisions on criteria for the sustainable use of biomass and the establishment of special zones for the accelerated development of renewable energy. The analysis shows the growing challenges related to the need to harmonize various values and priorities present in the policies of the European Union. The paper presents the dynamics and multidimensionality of EU policies in relation to the implementation of the sustainable development strategy. In this context, the legal significance of the principle of sustainable development has been reflected upon, with the conclusion that it serves to integrate the various principles of EU law and the fundamental rights guaranteed by EU law.