A parametric study on the performance characteristics of an evacuated flat-plate photovoltaic/thermal (PV/T) collector. (April 2021)

• Record Type: Journal Article
• Authors: Hu, Mingke; Guo, Chao; Zhao, Bin; Ao, Xianze; Suhendri, ; Cao, Jingyu; Wang, Qiliang; Riffat, Saffa; Su, Yuehong; Pei, Gang
• Is Part Of: Renewable energy. Volume 167(2021)
• Page Start: 884
• Page End: 898
• Publication Date: 2021-04
• Subjects: Solar energy -- Evacuated flat-plate solar collector -- Photovoltaic/thermal -- PV/T -- Parametric analysis; Renewable energy sources -- Periodicals; Power resources -- Periodicals; Énergies renouvelables -- Périodiques; Ressources énergétiques -- Périodiques; 333.794
• DOI: 10.1016/j.renene.2020.12.008
• Languages: English
• ISSNs: 0960-1481

Abstract

Abstract: An evacuated flat-plate photovoltaic/thermal (E-PV/T) collector was proposed. The inner space of the E-PV/T collector is vacuumed to suppress non-radiative heat losses, thus increasing thermal efficiency of the collector. Therefore, the E-PV/T collector has the potential to simultaneously deliver electricity and heat at high temperatures. A mathematic model was developed to evaluate the performance of the E-PV/T collector. The effect of some key parameters (e.g., initial water temperature in the water tank, vacuum degree, long-wave panel emissivity, and temperature coefficient of solar cells) on the performance of the E-PV/T system was investigated and the results were compared with a normal flat-plate PV/T (N-PV/T) system. Results suggest that the vacuum helps to enhance the total efficiency by nearly 10% points in high-temperature conditions (>80 °C). The vacuum degree of the upper space exerts a greater effect on system efficiencies compared to that of the lower space. Lower long-wave panel emissivity and greater temperature coefficient of the solar cell promote the performance of the collector. By lowering the long-wave panel emissivity from 0.95 to 0.05, the total efficiency soars from 26.82% to 61.20%. This study may help to guide parametric optimization and operation strategy of flat-plate PV/T collectors for high-temperature applications. Highlights: An evacuated flat-plate photovoltaic/thermal (E-PV/T) collector was proposed. The non-radiative heat loss is deeply suppressed owing to the vacuum. The total efficiency is increased by nearly 10% points (>80 °C). The thermal efficiency at zero-reduced temperature is 45.7% for the E-PV/T system. Long-wave emissivity of the PV/T panel profoundly affects the thermal efficiency.