Temporal-Spatial Structure and Influencing Factors of Urban Energy Efficiency in China's Agglomeration Areas

Energy efficiency has proved to be effective in mitigating greenhouse gas emissions and is significant to carbon neutrality targets. Urban agglomeration is the major engine of urbanization supporting economic growth. To optimizing the spatial exchange structure to improve regional energy efficiency by integrating the total factor energy efficiency model and social network analysis, this study constructs the spatial network of energy efficiency among cities within five major urban agglomerations in China for the period 2011-2018 and investigates their spatial association characteristics. The influencing factors of each spatial network structure are also explored by the quadratic assignment procedure method. The findings show that the spatial association of energy efficiency within each urban agglomeration presents a typical network structure, but with considerable disparity among urban agglomerations. Most cities in the Yangtze River Delta and Pearl River Delta are closely connected with each other, while the surrounding cities in the areas of Beijing-Tianjin-Hebei, Chengyu and the Middle Reaches of the Yangtze River highly depend on their corresponding central cities. The spatial adjacency and GDP per capita determine the urban spatial relationship of the energy efficiency within urban agglomerations. In addition, the spatial correlation of urban energy efficiency in the Beijing-Tianjin-Hebei, Chengyu and Middle Reaches of the Yangtze River areas is also affected by the differences in energy consumption, capital stock, number of labor force and pollutant emission. Some suggestions for improving urban energy efficiency are discussed.