For cities to confront the challenges of fossil fuel depletion, increasing energy costs and rapid climate change, it is inevitable to develop and implement urban energy management solutions for their sustainable future. This publication is a training companion developed originally for training courses at the International Urban Training Centre in the Republic of Korea. This Sourcebook addresses sustainable urban energy solutions from a system’s perspective, as a three-step process - energy conservation, energy efficiency and renewable energy. Energy conservation asks the question, “do we need to consume a given good/service?” Energy efficiency asks, “what would be the best possible way to consume the same good/service”, while renewable energy asks, “could there be sustainable renewable energy alternatives for fossil fuels”.