Many economies of APEC are undergoing rapid urbanization, and their energy demands are growing fast. Simultaneously, economies need to face the challenge of global climate change. Therefore, Low-carbon Energy System is a proactive option, which aims at energy efficiency, clean utilization and large-scale renewable energy consumption
as the background. It is composed of multiple types of energy systems and will realize the organic coordination of production, transmission, distribution, transformation, storage, consumption and other links of different energy forms in multiple space-time scales. Research on its forms will help cities improve the energy efficiency of cities, reduce the cost of energy supply and solve the problem of using renewable energy. This research will help people to use renewable energy meets demands better, and understand how the system contributes to cities’ sustainability and how cities take the road of sustainable development in the APEC region.