Energy demands of cities need to be met more sustainably. This book analyses the technical and social systems that satisfy these needs and asks how methods can be put into practice to achieve this. Drawing on analytical tools and case studies developed at Imperial College London, the book presents state-of-the-art techniques for examining urban energy systems as integrated systems of technologies, resources, and people. Case studies include: * a history of the evolution of London's urban energy system, from pre-history to present day * a history of the growth of district heating and cogeneration in Copenhagen, one of the world's most energy efficient cities * an analysis of changing energy consumption and environmental impacts in the Kenyan city of Nakuru over a thirty year period * an application of uncertainty and sensitivity analysis techniques to show how Newcastle-upon-Tyne can reach its 2050 carbon emission targets * designing an optimized low-carbon energy system for a new UK eco-town, showing how it would meet ever more stringent emissions targets. For students, researchers, planners, engineers, policymakers and all those looking to make a contribution to urban sustainability.