There is a certain synergy in the field of legal regulation of international energy law and international environmental law, which is being formed under the framework of modern international law. This synergy is based on the concept of sustainable development, namely, its component - the sustainable energy development. We also offer Green Energy concept, which is based on the concept of sustainable development and provides for a joint legal regulation of the use of environmentally friendly energy sources, environmentally friendly and energy-efficient uses of traditional energy sources and the development of new energy sources. This concept has two components: first, it is implemented in the sphere of international relations, as one element of the concept of sustainable development, namely, the "Sustainable Energy" (through the adoption of various political acts), and secondly, implemented under international law through a series of international legal instruments and customary rules. The author researches the role of international organizations in the implementation of Green Energy concept; particularly, organizations, such as IRENA, ITER, IEA. It is noted that it is too early to talk about the creation of a single institutional system here, as well as highlighted the absence of a unified international intergovernmental organization, the competence of which would be directly related to the whole Green Energy sphere. The special kind of transboundary harm is considered - the ecological and energy harm, as well as the implementation of international legal responsibility in Green Energy; in particular for the damage caused by climate change, including the rise of the sea level. The role of international judicial institutions in the implementation of the Green Energy concept is studied. Furthermore, the author investigates the function of the Green Energy concept under the framework of the EU and its relations with other states. There is a special analysis conducted to study the perception of acque communitaure in the sphere of energy and environmental protection by Ukraine, particularly, when implementing the provisions of the Association Agreement with the EU (2014).
