Tracking embodied energy flows of China's megacities via multi-scale supply chains

Urban energy requirements not only involve energy supplies within self-boundaries, but also impose huge demands via domestic and global supply chains. By constructing a multi-scale input-output model, this study depicts embodied energy uses of China's four megacities including urban, national, and global scales. The total embodied energy requirements of Beijing, Tianjin, Shanghai, and Chongqing are 8576.61, 6309.56, 11448.19, and 6941.43 PJ, respectively. Shanghai has the highest embodied energy use per capita (464.24 GJ), followed by Tianjin (447.49 GJ), Beijing (390.91 GJ), and Chongqing (220.78 GJ). Fixed capital formation accounts for above 70% of local energy requirements in Chongqing as the leading final demand category, while Urban household consumption in Shanghai accounts for nearly 40% of its local energy requirements. More than 20% of energy requirements in Beijing are imported from foreign economies, while about 10% of embodied energy uses in Shanghai are exported to other countries, mainly due to their location advantages and economic openness. Through depicting energy requirements of urban economies, this study is essential to recognize visible and embodied energy uses along multi-scale supply chains and address cross-boundary potentials of energy saving at urban, national, and global scales.

Automated summary

This study utilizes a multi-scale model to analyze the energy usage of China's four megacities at urban, national, and global scales. The findings reveal that Shanghai has the highest per capita energy usage, while fixed capital formation is the leading source of energy demand in Chongqing. Furthermore, over 20% of Beijing's energy requirements are imported from foreign economies, and approximately 10% of Shanghai's energy usage is exported to other countries.