Life cycle carbon emission flow analysis for electricity supply system: A case study of China

The carbon emission embodied in trade is fundamental for allocation of responsibility between producers and consumers. This paper quantitatively analyzes embodied carbon emissions along the life cycle of electricity supply, based on network theory. A modified carbon emission flow model is established, based on life cycle assessment considering power losses. There is also a case study of China's interregional electricity supply system in 2010, focusing on two carbon emission carriers, electricity coal transportation and electricity transmission. Results show that the total carbon emission flow reached 169.355MtCO2eq, i.e., 4.67% of the life cycle carbon emission. Of this, 61.1% was carried by electricity coal transportation before power generation and transmission, owing to an uneven distribution of coal resources. The eastern and southern regions are the major net sinks of carbon emission flows, representing 52.9% and 27.8% of the total, respectively, because of their enormous energy imports. In contrast, the Sanxi region and central China are major net sources of carbon emission flow. The proposed model may help allocate environmental responsibility among different regions, to guarantee balanced trans-regional development.