Environmental efficiency assessment of China's integrated power system under the assumption of semi-disposability

As the largest terminal carbon emitter in China, power industry is crucial for achieving carbon peak by 2030 and carbon neutrality by 2060, and constructing a sustainable society. To scientifically evaluate the environmental efficiencies of the regional power system, this study proposes a modified dynamic network slacks-based measure (DNSBM) model based on semi-disposability. It investigates the effects of the new round of power system reform by measuring the environmental efficiency of China's 30 provincial administrative regions' power system from 2014 to 2017. The results show the following: (1) The semi-disposability assumption performs better in objectivity and gauging the performance of decision-making units than the weak or strong disposability assumptions. (2) The ratio of renewable energy is positively correlated with the environmental efficiency and its decomposition indicators. Furthermore, the establishment of the power market helps to improve the environmental efficiency of the power system. (3) The new round of power system reform launched in 2015 has significantly improved the efficiencies of generation and distribution divisions. However, the efficiency of the transmission division changes slightly due to the heterogeneity of factors affecting the development of the regional power system.