With the advancement of the “carbon peaking” and “carbon neutrality” objectives

concerns regarding carbon emissions in energy system dispatching have attracted much attention. The integration of electricity and gas systems (IEGS)

with carbon capture power plants and power-to-gas (CCPP-P2G) facilities can facilitate flexible dispatching of multiple energy sources. This integration is conducive to the low-carbon and economically efficient operation of IEGS. Current research did not comprehensively consider the emission mitigation responsibility of the source-demand side. A bi-layer decentralized low-carbon optimal dispatching model on both source and demand sides is proposed in this paper. On the demand side

the carbon emissions and carbon caps are allocated based on marginal carbon intensity. Then a low-carbon demand response mechanism considering step-based carbon price is established to explore the low-carbon potentials of electrical and natural gas loads. An optimal dispatching model

incorporating carbon emission constraints

is formulated on the source side through the analysis of the operational characteristics of CCPP-P2G. Furthermore

the decentralized Alternating Direction Method of Multipliers (ADMM) algorithm is employed to solve the bi-ayer optimal model while protecting the data privacy of both IEGS operators and users. Case studies validate the environmental and economic benefits of the proposed low-carbon dispatching model.