精确核算产品碳足迹依赖具有适宜计算颗粒度并可随时间变化的电碳因子，分时分区电碳因子计算及应用成为行业性研究热点，有助于精细化计算电碳因子、丰富电碳因子应用场景、加强产品碳足迹核算管理。本文论述了分时分区电碳因子在产品碳足迹核算中的重要作用，结合电力系统生产运行实际建立了分时分区电碳因子的计算方法和应用流程；以江苏省为例展示了分时分区电碳因子的详细计算过程，从季节变化、典型日各时段差异、不同地级市分布情况等方面分析了该省份电碳因子的时空变化特性。进一步从优化产品碳足迹核算的基础参数、完善碳足迹核算标准与碳减排政策体系、促进更加绿色低碳的产品生产模式等方面展望了分时分区电碳因子在产品碳足迹核算中的应用前景。建议在推动分时分区电碳因子应用、加强火电碳排放的连续在线监测、制定产品碳足迹核算标准、建立与国际接轨的产品碳足迹核算认证体系等方面采取行动，全面加强我国产品碳足迹核算工作。

Accurately calculating the carbon footprint of products relies on an electric carbon factor with appropriate calculation granularity and time-varying characteristics. The calculation and application of time- and area-specific electric carbon factors have become a research hotspot in the industry, which helps refine the calculation of the electric carbon factor, enrich its application scenarios, and strengthen the management of product carbon footprint accounting. This study analyzes the important role of time- and area-specific electric carbon factor in product carbon footprint accounting, and establishes a calculation method and application process for the factor based on actual production and operation of power systems. Taking Jiangsu Province as an example, the detailed calculation process of the time- and area-specific electric carbon factor was demonstrated, and the spatiotemporal variation feature of the factor was analyzed from the aspects of seasonal changes, differences in typical days at different time periods, and distribution of different prefecture level cities. Furthermore, the application prospects of the time- and area-specific electric carbon factor in product carbon footprint accounting were discussed from the aspects of optimizing the basic parameters of product carbon footprint accounting, improving carbon footprint accounting standards and carbon reduction policy systems, and promoting greener and low-carbon product production models. It is recommended to take actions in promoting the application of the time- and area-specific electric carbon factor, strengthening the continuous online monitoring of thermal power carbon emissions, developing product carbon footprint accounting standards, and establishing an internationally aligned product carbon footprint accounting certification system, thus to comprehensively strengthen the product carbon footprint accounting in China.