A low-carbon optimization of integrated energy system dispatch under multi-system coupling of electricity-heat-gas-hydrogen based on stepwise carbon trading

To achieve efficient energy utilization and reduce systemic carbon emissions, this paper presents a multi-timescale, low-carbon optimal scheduling strategy for an integrated energy system (IES) with a high degree of coupling among combined heat and power (CHP), carbon capture systems (CCS), power-to-gas (P2G), and hydrogen energy. It is developed with a stepped carbon trading mechanism. First, the study analyzes the characteristics of the coupling model and offers an optimized model of the operational management processes associated with hydrogen energy. Then, to promote the integration of hydrogen energy in the novel energy system, the analysis evaluates the impacts of hydrogen-fired power generation, under varying fixed hydrogen doping ratios, on the low-carbon and economic performance of the IES. It further explains the related mechanisms. Finally, to minimize source and load prediction errors on optimal system scheduling, the study proposes a day-ahead low-carbon optimal scheduling model. Case study results confirm that the proposed model and strategy enhance the operational the IES flexibility by facilitating multi-system coupling across electricity, heat, gas, and hydrogen. This enhanced ability to utilize multiple, complementary energy sources improves both the utilization of renewable energy sources and the economic and low-carbon performance of IES.