The energy transition consisting in a change in the management model and a shift from brown to green economy has been observable in the EU since the beginning of the first decade of this millennium. The climate policy established by the EU authorities prioritises resource-efficient, low-carbon and sustainable technologies. The notion of sustainable energy is one of the terms that emerge in the relevant literature in connection with the energy transition. However, it has not been specified yet and its origin, sense, scope, area and components have not been discussed properly. Therefore, the aim of this paper is to define the notion of sustainable energy, its scope and area, beginning with the determination of the essence of sustainable management and ending with the identification of components of the sustainable energy paradigm. The first part of the paper specifies and defines the notion of sustainable management taking place in the sustainable economy. Subsequently, according to the iterative method subsequent components of sustainable energy are defined, such as sustainable energy development or sustainable energy system. The final part presents the scope and area of the sustainable energy as well as its paradigm. The leading research method applied is the iterative approach, methodology of systemic analysis and multi-level, multi-aspect and – at the same time – holistic approach to problems observed.