Low-carbon optimization scheduling of a CCS-P2G-HFC integrated energy system with 2D-DR under multi-mechanism collaboration

To address the challenges of low-carbon economic dispatch in Park-Level Integrated Energy Systems (PIES) under carbon neutrality targets, this paper proposes a multi-energy flow collaborative scheduling model that incorporates a Stepped Carbon Trading (SCT) mechanism and Green Certificate Trading (GCT). By developing an interactive framework that integrates the Carbon Capture System-Power-to-Gas-Hydrogen Fuel Cell (CCS-P2G-HFC) technology chain with a Two-Dimensional Demand Response (2D-DR) mechanism, the model enables balanced optimization of economic performance, carbon reduction, and operational flexibility in energy systems. First, a collaborative architecture for PIES encompassing "source-grid-storage-load" is constructed. The source side integrates diverse energy supplies, including renewables, electricity, and natural gas. The grid side couples energy conversion units such as CCS, P2G, HFC, and Combined Heat and Power (CHP). The storage side develops a coordinated storage model for electricity, heat, gas, and hydrogen. The load side incorporates horizontal DR based on temporal load shifting and vertical DR based on real-time multi-energy substitution. Second, a synergistic SCT-GCT mechanism is introduced, leveraging the incentive effects of tiered carbon pricing and green certificate subsidies to promote low-carbon system operations. Finally, the model aims to minimize the system's total cost, which is solved using the CPLEX solver. Simulation results indicate that the proposed strategy reduces overall costs by 13.8 %, increases renewable energy accommodation, lowers carbon emissions by 13.1 %, and decreases carbon costs by 9.4 %.