Low-carbon power system scheduling via nodal marginal carbon intensity-driven synergy between generation and demand sides

Nodal marginal carbon intensity (NMCI) quantifies the marginal change in system carbon emissions caused by nodal load variations and provides a potential signal for coordinating generation- and demand-side decarbonization. Because demand response (DR) changes nodal loads, it may alter the optimal solution and the active constraints of the generation-side scheduling problem, thereby changing the NMCI. This paper proposes a two-stage low-carbon scheduling framework that coordinates the generation and demand sides through NMCI. In Stage I, a DC-power-flow-based generation scheduling model jointly considers operating costs and carbon-emission costs of generators, and the NMCI and its corresponding invariance constraints are analytically derived for each scheduling interval. In Stage II, a low-carbon DR model incorporating an NMCI-based demand-side carbon tax is solved iteratively. The NMCI and its invariance constraints are updated whenever DR drives the system into a transition state, thereby enabling further exploitation of the demand-side emission-reduction potential while maintaining the feasibility of Stage I scheduling problem. Compared with traditional day-ahead generation-side scheduling without user-side DR, the NMCI-guided DR strategy reduces carbon emissions by 1.63% and 4.79% in the IEEE 30-bus and IEEE 39-bus systems, respectively, and outperforms the nodal static carbon intensity (NSCI)-based strategy in coordinating generation- and demand-side decarbonization.