Performance analysis and capacity optimization of a solar aided coal-fired combined heat and power system

Abstract Solar aided (coal-fired) combined heat and power (SACHP) system can realize the heat-power decoupling and maximize the utilization of renewable energy over the normal CHP system. The problems regarding the operation strategy and capacity optimization of such a SACHP system during the design process are addressed in this study. According to different heat and power demands, different operation strategies are proposed. A 330 MWe SACHP system with a 50 MWe wind farm attached is studied. Daily and annual performances are evaluated in terms of wind power accommodation, standard coal consumption (SCC), solar-to-power efficiency, and economic performance. Results show that compared with the 330 MWe CHP system, the SACHP system can increase wind power consumption (202.69 MWh) and reduce SCC (80.23t) during a heating season day. During a non-heating season day, the solar-to-power efficiency of the SACHP system reaches 21.18%. Besides, the solar field area and the thermal energy storage (TES) capacity have been optimized based on the enumeration method for maximizing the net annual revenue. The result indicates that when the TES capacity and the solar field area are 2 h and 21.48 × 104 m2, respectively, the SACHP system has the highest net annual revenue of 1.83 M$.