In a dynamically changing socio-economic environment with significant technical and technological progress, the notion of energy security takes on a new, broader meaning. Modern literature presents a variety of operational definitions of energy security. Most authors dealing with the issue of energy security expose its different aspects while standing in opposition to competing concepts. As a result, literature that addresses the problems of energy policy is becoming a platform for debates on the essence of energy security and the applicability of its various approaches to individual situations. There is no unanimity among authors with regard to the theoretical framework or the components of this notion. However, the issue of diversity of views is quite typical in social sciences and should not be taken negatively. Despite this, and perhaps contrary to the definitional wealth, experts in the field of energy policy constantly stress the necessity and urgency of undertaking work on the conceptualization of energy security. The aim of the article is a comprehensive review of the concept of energy security in the context of new trends in the development of the energy sector based on a narrative review of scientific literature. The main differences in the perception of energy security have been identified, and it has been pointed out that the “supply concept” of energy security is giving way to an approach in which energy is a factor initiating deep transformations of social systems by changing consumption patterns, reducing energy consumption, and forcing changes in economic systems by imposing energy efficiency standards and environmental standards.