The energy transition is Europe's flagship projects. It needs to provide sound answers to the climate and sustainability-, security of supply- and competitiveness imperatives. The energy transition corresponds to a large scale economic and cultural change. It encompasses sector coupling- linking up sectors that have ignored each other previously, like mobility and power. What is the meaning of digitalization, and how to face cybersecurity risks? Can Europe deliver a 50-55% decrease in Greenhouse Gas Emissions, as is the agenda of the new von der Leyen Commission?00This 2nd edition is not only updated, but also augmented with three new chapters : the first focusses on a European cross border carbon adjustment proposal. This mechanism is a center piece in the European Green Deal and as such debated intensively. Two other chapters present the value-add and next steps for European network codes and guidelines.00The book analyses the factors driving change: where are we on climate and sustainability, competitiveness and market, and security of supply? It presents the actors: what genesis of and what contemporary institutions for European energy policy, how is energy addressed by the national and by the European; what about the active customer paradigm and the many startups and business models changing, as well as NGOs? It investigates sectors: power, gas, mobility and the powerful push from digitalization. 00It should be noted that authors reflect their point of view, and not necessarily the one of the institution they are affiliated to.