This book provides a comprehensive account of EU's renewable energy policy development as it traces the agenda-shaping, policy formulation and decision-making phases of the EU's secondary legislation on renewable energy – that is the three successive directives of 2001 (RES-E), 2009 (RED), and 2018 (RED II). It also explores the EU's energy policymaking dynamics and assess integration outcomes of these three policymaking instances in the renewable energy field from a comparative perspective. Enriched with elite interviews with the Brussels policy community, and drawing on European integration and public policy literature, the proposed book will resonate with and offer relevant insights to students, scholars, stakeholders, and policymakers interested in EU energy policy, in particular, and European integration, in general.