Reducing China's energy consumption and CO2 emissions by more efficient use of energy

This manuscript aims to comprehensively analyze the potential of energy consumption and CO2 emissions reduction by the improvement of energy efficiencies at various nodes of China's energy system. First, based on exergy analysis, we map the energy flows of China from useful energy to passive systems to expand the exergy flow diagram developed in a previous study, which already includes sub-processes from energy sources, intermediate conversion, end-use devices, to useful energy. Based on that, we present an evaluation and comparison of the potential of energy and CO2 emissions reduction by efficiency improvements of power generation technologies, end-use devices, and passive systems. The results indicate a tremendous reduction potential by the improvements of passive systems. Besides, the efficiency improvement of coal power generation and coal burners can also bring considerable reductions. We also present an analysis of the magnification effect of passive systems, which illustrates that household appliances and illumination devices can bring large reductions by slight efficiency improvements.