Planning and operational optimization of a carbon-capture-integrated wind-PV-coal-storage combined heat and power system

To improve renewable energy accommodation and reduce carbon emissions in coal-dominated district heating systems, this study develops a carbon-capture-integrated wind-PV-coal-storage energy system supported by coal-fired combined heat and power (CHP) units. A unified modeling framework is established for wind power, photovoltaic generation, electrochemical energy storage, coal-fired CHP, post-combustion carbon capture, electric boilers, and the energy hub. Based on representative typical days in summer, spring/autumn, and winter, a capacity-planning model and an operational optimization model are formulated with the net life-cycle cost (LCC) as the objective function and solved using an improved beetle antennae search algorithm (IBAS). Under the typical-day planning condition, the optimal configuration is obtained as 22.5 MW of wind power, 15.5 MW of photovoltaic capacity, 17.5 MW of battery storage, 360 t/h of CO₂ capture capacity, and 9.2 MW of electric boiler capacity, corresponding to an LCC of 37.7 M$. Further scenario analysis shows that the direct steam extraction heating mode achieves the lowest LCC, the lowest coal consumption rate for power supply, and the highest exergy efficiency, while the electric-boiler-only mode yields the lowest carbon emissions and the highest clean energy share at the expense of significantly higher system cost and poorer thermodynamic performance. The hybrid heating mode combining steam extraction and electric boilers provides a balanced compromise among economy, low-carbon performance, and operational flexibility.