Building energy system of carbon neutrality cities (2): Network

This article is the second in a series of articles on the building energy system of carbon neutrality cities, outlining new concepts, technologies and approaches for the power grid, heating/cooling and gas networks of urban energy systems in the context of carbon neutrality. It is emphasized that the future energy network is smart-grid-based and the three networks are integrated to form an energy internet in urban areas. The article reviews the flexibility of smart grids, the important role of heat pumps in smart grids, the load diversity in the energy bus (EBus) and the technologies to maintain EBus network water temperature, CO2-based district energy networks, and the technical issues such as preparation, delivery, storage of hydrogen fuel at district level.