Cities are responsible for approximately three-quarters of the world's energy consumption and they therefore play a major role in energy issues such as economic security and climate change. The CUE2015, with theme of “power your city with clean, affordable & reliable energy”, is to provide a platform focused on urban energy systems, covering the topics of energy supply, distribution, and end use; smart eco-cities, urban transportation with efficient energy and low emissions; microgrid and smart home; BIPV and renewable applications; urban waste to energy; nexus of energy-water; policy options etc. The event consists of two-day symposium for sharing the most recent progress of research in urban energy systems and one-day summit to engage all stakeholders for discussing how future urban energy systems can be implemented. The CUE2015 is organized by the international journal, Applied Energy, Applied Energy Innovation Institute and China Association for Science and Technology HOME Program (CAST/HOME) and hosted by Fujian Association for Science and Technology and co-organized by Chinese Society of Engineering Thermophysics, Beijing Institute of Technology, Future Energy Profile/Malardalen University Sweden.