Towards net-zero: Coupling carbon mineralization with seasonal energy storage in integrated energy systems planning

As climate change accelerates, alongside rising energy demands and intermittent renewable resources, integrated energy systems urgently require strategies that achieve deep carbon reductions while maximizing energy utilization. This study proposes an innovative low-carbon planning model that integrates advanced carbon mineralization technology with trans-seasonal thermal storage, enhancing both environmental and economic outcomes in integrated energy systems, by constructing a novel carbon reduction model that couples carbon capture power plants with power-to-gas conversion and mineralization processes, captured carbon dioxide is repurposed into stabilized carbonates and natural gas, thereby significantly enhancing carbon utilization. A seasonal thermal storage system based on underground caverns was constructed to utilize the thermal energy generated from the aforementioned carbon conversion reactions and power plant flue gases. By accounting for ambient temperature and static storage losses, the introduced cavern thermal storage model accurately simulates changes in stored thermal energy, effectively enhancing energy utilization efficiency and mitigating seasonal load fluctuations. Building on these foundations, a two-layer planning model was developed to integrate the proposed full-chain carbon reduction scheme, encompassing carbon capture, reutilization, waste heat recovery, and thermal storage. Simulation results of the regional energy system show that the methodology improves carbon utilization by 22.7 % and energy efficiency by 3.81 %, demonstrating the potential of the planning scheme to promote the transition of the energy system to net-zero carbon emissions.