Experimental investigation of a concentrating PV/T collector with Cu9S5 nanofluid spectral splitting filter

In the traditional PV/T collector, the temperature of thermal energy is always limited by the operation temperature of PV cells. Such a low-temperature thermal energy can hardly meet the demand in industrial application. To breakthrough the temperature limitation, a concentrating PV/T collector with fluid based spectral splitting filter is developed in present work. The oleylamine solution of Cu9S5 nanoparticle is adopted in the filter to harvest the moderate-temperature heat The performance of the collector is investigated by an outdoor experimental system. The results indicate that the PV efficiency of Si cell itself can be improved when the Cu9S5 nanofluid is employed as the optical filter in the collector. The maximum overall efficiency of present PV/T collector is 34.2%, which is 17.9% higher than that without a filter. The present collector has successfully obtained thermal energy with a temperature higher than 100 degrees C, which verifies the potential of Cu9S5 nanoparticles in fluid-based spectral splitting technique. Moreover, the particle concentration has a significant influence on the performance of hybrid PV/T system. The ratio of heat to electricity in PV/T system can be adjusted by changing the particle concentration to meet the requirements in various applications. In addition, the glass cover surrounding outside of the optical filter can improve the thermal efficiency, but it also increases the optical loss of the system due to the reflection on the surface of glass. Therefore, to realize higher performance, it is necessary to employ the glass with anti-reflection layer in the collector. (C) 2016 Elsevier Ltd. All rights reserved.