Carbon footprint scenarios for electricity mix in China

The biggest increase in carbon emissions took place in the power sector, accounting for more than 40% of global carbon emissions. Identifying critical sectors of carbon emissions in the upstream power sector and mapping out emission reduction pathways are core components of achieving supply chain-wide carbon reductions in China. However, the path to achieving supply chain-wide carbon reductions in China from the provincial perspective is still unclear. This study quantifies the embodied carbon emissions of different power generation technologies by region using a multi-regional input-output-based hybrid approach. The critical upstream sectors that indirectly drive or transport large amounts of carbon emissions through supply chains are identified using both consumption-based and betweenness-based methods. The changes in supply chain-wide carbon emissions of the power sector by region under different emission reduction policy scenarios are also examined. The results indicate that the solar power sector brings the highest carbon reduction benefits, with an average carbon intensity of 1.25 t/10000 yuan. Significant differences in embodied carbon intensity across provinces for the same type of power generation sector are observed, and there is a mismatch between current installation and carbon reduction targets in the coal-fired and wind power sectors. Critical sectors of carbon emissions in the upstream power sector are concentrated in the energy sector and energy-intensive sectors, while the electrical machinery and equipment sector is also key to alleviating environmental pressures as an important upstream carbon transmission sector. Besides, the implementation of the "Replacing Small Generation Units with Large Ones" policy at the provincial level, especially in northwest China, and “further enhancing the supply capacity of clean energy” can effectively promote the emission reduction of the whole supply chain in the power sector. The results presented in this paper may provide a reference for the provincial government to rationally plan future low-carbon transformation paths of the power sector.