In a context of multiple crises, European Union (EU) energy policy is often identified as one of the few areas still exhibiting strong integration dynamics. However, this policy domain is not exempt from contestation and re-nationalization pressures. This collection seeks to understand better the contradictory integration and fragmentation tendencies by problematizing the notion of authority. While authority lies at the heart of European integration theory, less attention has been given to explaining when and why previously conferred authority becomes contested and how authority conflicts are addressed. In framing this collection, we build on sociological approaches to examine systematically the conferral of authority (what counts as authority and how it comes to be recognized) and its contestation (the types of contestation and strategies for managing authority conflicts). We focus this analytical discussion on the Energy Union, being an example of ‘hybrid area’, which sits uncomfortably at the nexus of different policy areas