Energy is central to sustainable development. It has huge environmental, social, and economic impacts, such as its influence on climate change, poverty reduction efforts, industrial and agricultural productivity and environmental and human health. The development of strategies towards a sustainable energy transition is one of the most important world challenges of the twenty-first century. The choices that we will make in the coming years about energy will determine what world future generations will inherit. This book gives an overview of the key issues, strategies, operational guidelines and policy implications of current research on the transition to more sustainable energy consumption. It investigates the important issue of the relation between human activities, energy systems and energy use. It addresses the environmental, social and economic impacts of energy consumption and their interrelationships. This book was written by academic and research experts in the field of energy, and they have developed strategies for an energy sustainable plan for the main energy-intensive sectors: energy production, transportation, buildings, agriculture and domestic appliances. The best opportunities and solutions for energy demand reduction are shown, including energy efficiency improvement, increases in the share of renewable energy sources, technological progress and behavioural changes in the field of energy. The aim of this work is to guide the reader toward more efficient policies and actions that will actually improve the future. The book also addresses the different issues faced by developing and developed countries, as well as their relative respective solutions. It presents various alternative pathways that are open to our societies. The methods of energy consumption assessment and modeling approaches are also discussed. All those who are interested in energy challenges will find practical knowledge and operational solutions in this book, providing a solid foundation for making well-informed choices in the future, as individuals and as societies.