End-to-End Tri-Stage Low-Carbon Planning of Coupled Electricity-Hydrogen-Gas-Transportation Systems Toward Hydrogen-Fueled Mobility

In the context of global climate change and the urgent transition of energy systems, developing clean energy and reducing carbon emissions have become critical for sustainable development. To address the challenges of fossil fuel dependency and insufficient hydrogen infrastructure, this paper proposes a tri-stage low-carbon planning model for a coupled electricity–hydrogen–gas–transportation (EHGT) system. The model minimizes the marginal abatement cost of carbon (MACC) to balance the trade-off between decarbonization benefits and the expansion costs. It incorporates the phased retirement of coal-fired units and fossil fuel stations, and utilizes the carbon emission flow (CEF) model to guide the siting of hydrogen facilities and the construction of hydrogen highways. Two real-world case studies are conducted in the Beijing–Tianjin–Hebei (BTH) and Chongqing regions to verify the model’s effectiveness in decarbonization and its practical applicability. The results demonstrate that the proposed framework can generate actionable planning schemes across both demonstration and promotion stages, highlighting its capability to support the deployment of low-carbon infrastructure and coordinated development of hydrogen systems under long-term transition scenarios.