Real-time performance characteristics of a full-scale spectral splitting hybrid Photovoltaic/Thermal system

•A full-scale spectral splitting photovoltaic/thermal system is tested experimentally.•Ethylene glycol, ethanol and de-ionized water are used as spectral filter fluids.•Effect of air gaps and PV back cooling on thermal performance is analyzed.•Water shows the best results with maximum overall efficiency with back cooling arrangement.•Economic study shows the merit of the system for future commercialization. In hybrid photovoltaic (PV)/thermal system, to achieve high thermal performance, liquid absorbers based spectral splitting method has been reported recently. Thecurrent level of technology for such novel hybrid systems is limitedto either theoretical work or laboratory scale prototype testing. Experimental studies that specifically focus on real-time monitoring of the performance characteristics of spectral splitting systems are necessary. We performed outdoor testing on a full-scale spectral splitting hybrid photovoltaic/thermal system under Indian climatic conditions. The performance of hybrid system was analysed considering different air gaps between PV panel and the thermal system, and with and without back cooling arrangement. The study utilised commonly used liquid filters such as ethylene glycol/water mixture (50–50 vol%), ethanol/water mixture (50–50 vol%), and de-ionized water considering their high transmittance in visible and strong absorption in infra-red regions of solar spectrum. The experimental results showed that the thermal system experienced a maximum temperature gain of 54.5 °C with back cooling arrangement. Furthermore, the PV panel in hybrid system showed a significant lower average surface temperature as compared to the bare photovoltaic panel at an air gap of 3 cm. The experimental study observed a maximum overall efficiency of 72.7 % with de-ionized water as spectral splitter with back cooling arrangement.The proposed hybrid system is able to decouple the temperature of the thermal system and PV processes so that the combined performance is enhanced.