Techno-economic analysis of a novel solar-based polygeneration system integrated with vanadium redox flow battery and thermal energy storage considering robust source-load response

In this study, a novel solar-based polygeneration system incorporated with a partially covered parabolic trough photovoltaic thermal (PCPVPVT) collector, vanadium redox flow battery (VRFB), thermal energy storage, and absorption chiller/heat pump is proposed. A robust energy management strategy is developed to alter the operating states of the system to respond to the inevitable intermittent source inputs and varying demands throughout the year. Furthermore, a comprehensive comparison of the techno-economic performance differences between the novel system and the Power to Hydrogen to Power (P2H2P) combined cooling, heating, and power (CCHP) system is carried out. In addition, the sensitivity analysis of the key technical and external economic parameters as well as a multi-objective optimization are investigated. The results illustrate that: the charging, discharging, and round-trip efficiencies of the VRFB unit reach 88.99%, 88.23%, and 78.52%, respectively, and the current of the VRFB has significant effects on the termination voltage, charge and discharge time, efficiencies, and stored and output energy of the VRFB. The PV coverage ratio of the PCPVPVT and the capacity of the VRFB unit considerably affect the system's thermodynamic and economic performance. The exergy efficiency of the proposed system is always greater than that of the P2H2P CCHP system because the efficiency of the VRFB with 78.52% is significantly higher than that of the P2H2P electricity storage with 41.73%, and the maximum difference reaches 4.25%. The levelized cost of energy of the present system is 0.0503 $/kWh, which is less than that of the P2H2P CCHP system by approximately 6.85%, indicating superior economic strengths.