Abstract:

The electricity carbon emission factor, as a core indicator for measuring the low-carbon progress of power systems, has become an important basis for the international carbon accounting system and green trade rules. Firstly, the core influencing factors for the electricity carbon emission factor were identified, and a method suitable for quantitatively assessing the contribution of the electricity carbon emission factor was proposed. Secondly, the contributions of different factors driving the decline of China's electricity carbon emission factor were quantitatively assessed, and the differences and reasons for the electricity carbon emission factors between China, Japan, and Germany were compared and analyzed. Finally, the potential for the decline of China's electricity carbon emission factor and the characteristics of the contributions of the main driving factors were quantitatively assessed. The study shows that from 2005 to 2022, China's electricity carbon emission factor decreased by 35%, with the increase in the grid cleanliness and the improvement of power generation efficiency being the two main influencing factors, contributing 19% and 14% respectively. China's electricity carbon emission factor is 22.5% higher than Japan's, primarily due to its heavy reliance on coal for thermal power. It is 53.5% higher than Germany's, mainly because of a lower clean energy share. Enhancing the grid cleanliness is the key driver for reducing China's electricity carbon emission factor, contributing over 80% to the decline. After new energy expansion reaches a certain scale, optimizing the structure of thermal power will also play a significant role.

Key words: power sector, electricity carbon emission factor, driving factors, contribution rate