Cooperative bargaining-based integrated electricity and gas system planning with CCUS

Integrated Electricity and Gas System (IEGS) considers the coupling between electric power and natural gas systems, which is an approachable pathway to improve the synergy of different energy systems, thus helping the decarbonization of both sectors. This article proposes a cooperative bargaining-based planning framework for IEGS, which explicitly considers Carbon Capture, Utilization, and Storage (CCUS) technologies and multi-agent interactions. The proposed model incorporates physical process constraints of MEA-based Carbon Capture and Storage (CCS) and synthetic methane production, jointly optimizing investment and operation strategies for Carbon Capture Power Plants (CCPP), Renewable Energy (RE) suppliers, and Carbon Utilization (CU) units. To ensure scalability and privacy, a two-stage Alternating Direction Method of Multipliers (ADMM) algorithm is developed, in which the profit maximization subproblem is first solved under physical constraints, followed by Nash bargaining to determine retail electricity and carbon prices and allocate surplus in a transparent manner. Unlike previous IEGS planning studies that assume a single operator, the proposed framework reflects the decentralized ownership and information asymmetry in industrial parks and integrates a physics-consistent linearization of the carbon capture process. Simulation results demonstrate that the bargaining-based planning model effectively increases cooperative surplus, ensures fair surplus allocation with reliable convergence, and provides a scalable solution for multi-agent IEGS planning in evolving energy markets.