Estimating the environmental impacts of backup generation after power outages: A case study of China

Backup generators (BG) are indispensable to address the potential electricity security risks caused by extreme weather, cyber attack and infrastructure failure. Diesel generators, the major BG component, are more polluting than grid electricity, which are in the blind spot of environmental regulation and statistics. To contribute to better environmental policies for the electricity sector, this study estimates the environmental impacts of backup generation in China. A BG capacity evaluation model is firstly developed based on the safety design rules of different buildings. Then, an environmental cost assessment model is constructed to quantify the impacts of pollutant emissions from BG after power outages. At last, this paper uses an improved Monte Carlo method to re-examine the estimated results considering multiple uncertain factors and analyzes their contributions to the total cost variance. Our major findings are: (1) The estimated total BG capacity is 169.46 GW in 2020, representing 7.70% of the total generation capacity in China. (2) The environmental cost of BG generation is 6.60 billion yuan in 2020. (3) Sichuan and Hubei suffer the highest environmental impacts at the provincial level.