Graph-Based Calculation of Residual Carbon Intensity in Regional Power Grids Considering Green Power Transactions

The calculation of electricity carbon intensity serves as the foundation for setting and achieving carbon emission reduction goals. Understanding electricity carbon intensity from various dimensions is instrumental in formulating and advancing sustainable development strategies. By utilizing regional residual electricity and local power generation to calculate carbon emissions, the actual carbon emission status of the regional power system can be accurately and comprehensively assessed. This supports the formulation of climate change mitigation policies and the promotion of green energy capacity. This paper initially constructed a graph data model integrating the power grid and carbon emission models based on a graph database. Subsequently, through the quantitative comparison of power generation and load in the regional power grid, the grid was categorized into three types: power output region, power input region, and power self-balancing region. Following this, a calculation method for the residual carbon emission intensity in regional power grids considering green energy transactions was proposed for each type of regional power grid. This addressed the deficiency in the current accounting methods for residual carbon in regional power systems when considering scenarios involving green energy transactions. Finally, using the provincial-level power grids as target regions, simulation data for a trading cycle with green energy was employed to calculate residual carbon emission intensity. A comparative analysis was conducted with the power generation carbon intensity and electricity consumption carbon intensity within the regional power grid.