This book provides a comprehensive exploration of some of the most critical issues regarding the EU's Energy Union policy. Applied European energy policies face a number of challenges ranging from the geopolitics of energy and energy regulation, to climate change, advancing renewable and gas technologies, and consumer empowerment structures. This book takes a multi-dimensional look into some of these vital issues regarding the European energy sector with a special focus on the effects the Energy Union policy has in two sensitive regional systems, Southeastern Europe and the Eastern Mediterranean. Energy, being by definition a multi-disciplinary field, presents a challenge for readers of any specific disciplinary background that need to grasp an overall understanding of the various aspects of this exciting sector. This book's objective is to offer the opportunity for readers to get a quality, hands-on overview of the Energy Union by the professionals and academics that interact with it on a daily basis.