Tracking Carbon Flows from Coal Mines to Electricity Users in China Using an Ensemble Model

Accuratelytracking carbon flows is crucial for preventing carbonleakage and allocating responsibility for reducing CO(2)eqemissions. In this study, we developed an ensemble model to effectivelytrack carbon flows within China's power system. Our approachintegrates coal quality tests, individual power plant datasets, adynamic material-energy flow analysis model, and an extended versionof an interconnected power grid model that incorporates transmissionand distribution (T & D) losses. Our results not only provide accuratequantification of unit-based CO(2)eq emissions based on coalquality data but also enable the assessment of emissions attributedto T & D losses and emission shifts resulting from interprovincialcoal and electricity trade. Remarkably, for CO(2)eq emissionsfrom coal-fired units, the disparity between the guideline and ourstudy can be as high as [-95%, 287%]. We identify Guangdong,Hebei, Jiangsu, and Zhejiang provinces as the major importers of bothcoal and electricity, responsible for transferring nearly half oftheir user-based emissions to coal and power bases. Significantly,T & D losses, often overlooked, contribute to 15-20% of provincialemissions at the user side. Our findings emphasize the necessity ofup-to-date life cycle emissions and spatial carbon shifts in effectivelyallocating emission reduction responsibilities from the national levelto provinces. This study reveals the impactof coal quality and T & Dlosses on life cycle CO(2)eq emissions at the power userside.

Automated summary

In this study, an ensemble model was developed to accurately track carbon flows within China's power system, enabling accurate assessment of CO(2)eq emissions. By integrating coal quality tests, individual power plant datasets, dynamic material-energy flow analysis model, and an extended version of an interconnected power grid model, the study provides accurate quantification of emissions and evaluates emissions related to transmission and distribution losses and interprovincial coal and electricity trade. The study highlights the importance of considering up-to-date life cycle emissions and spatial carbon shifts when allocating emission reduction responsibilities from the national level to provinces.