Thermodynamic evaluation of a combined cooling, heating, hydrogen, and power multi-generation system for full-spectrum solar energy utilization.

• A combined cooling, heating, hydrogen and power multi-generation system is proposed; • Low-grade solar energy in long wavelength is converted to high-grade chemical energy; • Up to 18.8% energy storage ratio and high dispatchability are achieved； • Primary energy saving ratio is 81.78% when compared to the reference system. Solar photovoltaic/thermal (PV/T) hybrid systems are considered energy-efficient and eco-friendly. However, conventional PV/T systems generate electricity with high power fluctuations and low-grade thermal energy. In this paper, dry reforming of methane (DRM) is introduced to convert low-grade thermal energy through chemical reaction and enhance the dispatchability of the PV/T system. A combined cooling, heating, hydrogen and power (CCHHP) multi-generation system that integrates the PV/T, DRM and CCHP (combined cooling, heating and power) is proposed to use the full-spectrum solar energy. Energy and exergy analysis under design and variable working conditions are conducted to analyze the system performance. The results reveal that the proposed system can achieve a high energy conversion efficiency of 61.34 % and 18.8 % energy storage ratio at direct normal irradiance (DNI) of 800 W·m−2. In addition, the system can save up to 81.78 % primary energy when compared with the reference system. This study can facilitate the better design and performance evaluation of PV/T hybrid systems. [ABSTRACT FROM AUTHOR]