The energiewende “made in Germany” is a relatively recent phenomenon, yet with a long germination period, going back to the 1970s, and it has attracted broad interest in many spheres, including academia, industry, and policy making. The previous chapters have provided insights into specific aspects of the process, and have sketched out possible pathways for future developments. The chapters of this book share among them the conviction that, while many obstacles have yet to be overcome, the energiewende is well underway, e.g. increasing the share of renewables in the electricity sector, or taking nuclear power plants from the grid without adverse impacts; however, significant challenges remain, e.g. increasing energy efficiency, and reducing the carbon footprint of the energy system as a whole. From a public policy perspective, the energiewende is well justified because it enhances the welfare of society. The objective of this chapter is to draw some cross-cutting lessons from the first period of the energiewende. Until recently, the focus of the energiewende was on the electricity sector, but what is required is an energy system wide approach. There are at least three decades before us in which further reforms, technical innovations, and political consensus will be required to make the energiewende a true success. The empirical evidence from the recent past, together with a technical and political assessment of the feasibility of the next reform steps, allows us to formulate 15 lessons, both summarizing the previous chapters and opening up perspectives on the future. This will be done following the book’s structure: Section 14.2 looks at lessons from the long-term analysis of energy and climate policies (Part I of the book). Section 14.3 focuses on the lessons from the ongoing energiewende in Germany (Part II), and Sect. 14.4 provides lessons on the interplay between the German setting and the low-carbon transformation at the European level (Part III). Section 14.5 discusses the findings, provides an outlook on the next phases, and concludes.