The need for a deep decarbonization of the energy sector and the associated opportunities are now increasingly recognized, with fossil fuel projects simultaneously becoming more risky business propositions. With large-scale wind and solar generation now being the cheapest options in many parts of the world, a deeply renewable electricity sector is predestined to become the main driver of this transition. Yet, misconceptions abound. In part, this can be traced back to the complexity of the electricity sector and the processes involved in its transformation, located at the intersection between grid design and operation, markets and regulations. This book is intended to provide some clarity in this matter, by taking the reader from the conceptual foundations of a deeply decarbonized electricity sector in part 1 to new strategies for the renewable energy transition in part 3. Insights into essential building blocks are provided in part 2 where the role of transmission, distributed generation, smart grids, demand response, storage, and forecasting are covered in some detail. The synthesis part 3 explores the connections between the mobility and electricity sectors, the design of renewable economies, and possible roadmaps for a world-wide transition to a deeply decarbonized economy. While striving to be technically rigorous, this book is also meant as an entertaining and inspiring read for researchers and advanced students, experts with the electric power industry, and decision makers in politics, industry and finance.