Optimization Strategy for Low-Carbon Economy of Integrated Energy System Considering Carbon Capture-Two Stage Power-to-Gas Hydrogen Coupling

To further optimize the low-carbon economy of the integrated energy system (IES), this paper establishes a two-stage P2G hydrogen-coupled electricity–heat–hydrogen–gas IES with carbon capture (CCS). First, this paper refines the two stages of P2G and introduces a hydrogen fuel cell (HFC) with a hydrogen storage device to fully utilize the hydrogen energy in the first stage of power-to-gas (P2G). Then, the ladder carbon trading mechanism is considered and CCS is introduced to further reduce the system’s carbon emissions while coupling with P2G. Finally, the adjustable thermoelectric ratio characteristics of the combined heat and power unit (CHP) and HFC are considered to improve the energy utilization efficiency of the system and to reduce the system operating costs. This paper set up arithmetic examples to analyze from several perspectives, and the results show that the introduction of CCS can reduce carbon emissions by 41.83%. In the CCS-containing case, refining the P2G two-stage and coupling it with HFC and hydrogen storage can lead to a 30% reduction in carbon emissions and a 61% reduction in wind abandonment costs; consideration of CHP and HFC adjustable thermoelectric ratios can result in a 16% reduction in purchased energy costs.