The impacts of heat-power cogeneration on air pollution: An empirical study based on the measures for the administration of heat-power cogeneration policy in China

Air pollution is a global environmental challenge that places a heavy burden on human health and socioeconomics. In China, a large amount of pollutant emissions is attributed to the use of coal for heating and power generation, which makes efficient energy utilization a critical task for air pollution prevention and control. This study systematically investigates the impacts of the Measures for the Administration of Heat-Power Cogeneration (HPC) policy on air pollution and its mechanism by applying the difference in differences (DID) model based on a panel data sample covering 296 cities in China from 2013 to 2020. The SO2 and NO2 concentrations based on satellite remote sensing data are both incorporated into our unified analytical framework. The empirical results reveal that compared with the nonpilot cities, the HPC policy can significantly alleviate SO2 and NO2 pollution by approximately 17.4% and 3.7%, respectively, which can also be confirmed by multiple robustness tests. Then, we also found that there are three main mechanism paths to the implementation of pollution mitigation by the HPC policy, including green technology innovation, energy structure optimization, and energy efficiency improvement. Furthermore, significant heterogeneity of the effectiveness of the HPC policy on SO2 and NO2 pollution control was captured, and the synergistic effect is more obvious in cities with large populations, "2 + 26 '' key cities, urban agglomerations, and low-carbon pilot cities. Moreover, we found that the roles of the HPC policy in NO2 abatement in low-carbon pilot cities and nonpilot cities did not show a significant difference. The findings of this paper can serve as useful policy references and inspiration for the systematic planning of HPC projects and provide a reference for other areas with severe air pollution.