Problem setting. The ever-increasing challenges to the European Union’s energy security, the steady increase in energy demand and the commitment to combat climate change make the promotion of renewable energy sources particularly relevant. The author of the article substantiates the thesis that currently the actualization of the use of ecologically clean energy sources already goes beyond the climatic context and has an economic and geopolitical basis. Analysis of recent researches and publications. In Ukraine and abroad, there is a rather illustrious list of scientists who worked on the study of the peculiarities of the regulation of ecologically oriented energy both in the whole world as a whole and in the EU in particular. They are specialists in international, environmental, climate law and EU law. S. Bilotsky, Ya. Benedyk, Yu. Shemshuchenko, Yu. Kogut, K. Huhta, S. Bruce, E. Grigorovic can be singled out separately. Of course, the given list is not exhaustive and contains only a few examples of scientists actively researching the issue of legal regulation of RES support in the European Union and the world. However, it is the actualization of the issue of expanding the use of RES that determines the need for further scientific research, in particular in the area of ensuring energy security in the EU. Purpose of the research is to study the EU regulatory framework in the field of ecologically oriented energy as an integral component of increasing the overall level of EU energy security in the context of modern geopolitical challenges, as well as its improvement after the start of the full-scale invasion of Ukraine by Russia on February 24, 2022, and the study of the results, which are obtained thanks to such normative transformations. The presentation of the main material of the article will relate to the justification of the need to increase the share of renewable energy sources in the energy use of the EU precisely after the start of a full-scale war between Ukraine and Russia. Article’s main body. The presentation of the main material of the article is primarily devoted to an overview of the modern legal regulation of the introduction of renewable energy sources in the EU, as well as to the justification of the importance and advantages of the transition to RES in the context of the modern geopolitical situation caused by the fullscale invasion of Russia into Ukraine and the main challenges arising in connection with this before the region. The author puts forward the thesis that one of the positive aspects of RES development will be the reduction of dependence on imported energy resources in general, and on Russian ones in particular. The problems of global implementation and mechanisms of RES implementation in the EU are briefly highlighted, emphasizing their positive effects. The author also highlights the list of measures necessary for the energy system to provide the EU member states with energy not from fossil fuels, but from ecologically clean sources that do not pollute the environment and do not affect climate change. The author emphasizes the need for active implementation and support of a policy focused on the development of RES, in order to ensure a sustainable, independent and ecologically clean energy future. Attention is drawn to mechanisms for financing and supporting projects aimed at the development of ecologically clean energy, which will allow the EU to cope with modern challenges in the energy sector. Conclusions and prospects for the development. The EU should focus its efforts on increasing the use of wind energy, solar energy, hydropower, geothermal energy and biomass (including peat) for the production of electricity and fuel, which should be based on the national energy strategies of the member states, taking full account of geographical, geological or climatic features, taking into account differences of each member state. Infrastructural compatibility and the development of innovative technologies in the energy sector should also become a priority of the EU member states. New technologies can help minimize the negative effects of climate change on the safety of citizens, and should also be taken into account in the design and operation of stations and networks that will run on renewable energy sources. In addition, it is necessary to ensure the arrival of significant public and private investments in the research and development of “green” technologies and alternative energy and the development of new capacities, in particular through the European Investment Bank and the European Structural Funds and the stimulation of sufficient investments from private donors.