Thermal performance analysis of a CuO nanofluid based spectral beam splitting Photovoltaic/Thermal system under real-world conditions

The study reports testing results of a full-scale spectral beam splitting photovoltaic/thermal system using CuO nanofluids (as spectral fluid) under real-world conditions. A comprehensive energy, economic, and environmental analysis confirms the system’s viability for its future commercialization. • Thermal and electrical performance testing of SBS-PV/T system under flow conditions experimentally. • Effects of mass flow rates and weight concentration of CuO-NPs were analysed. • SBS-PV/T system reported η ov ≈ 38.40 % with CuO-NFs at 4 mg. L -1 , and m f ≈ 0.035 kg. s −1 . • CuO-based PV/T system decreased COE/kWh by 20.4% against standalone PV system. Thermal performance of a nanofluid assisted spectral beam-splitting Photovoltaic/Thermal (SBS-PV/T) system is contingent upon the thermo-optical characteristics of beam splitting fluids. However, real–time prediction of thermal and electric performance of such SBS-PV/T systems under outdoor testing with flow conditions is still underexplored. The present study focuses on real–time thermal performance of a CuO nanofluids based SBS-PV/T system for its energetic, economic and environmental perspective during autumn season in India. CuO nanoparticles of sizes ∼ 25–55 nm were used to prepare nanofluids and further optical and morphological characterised using UV–VIS-NIR spectrophotometer and Field Emission-Scanning Electron Microscopy (FE-SEM) methods, respectively. The outdoor experiments were conducted to analyse the effect of CuO-NPs loading and mass flow rates on electrical and thermal performance parameters of SBS-PV/T system. A maximum temperature gain with CuO nanofluids was observed ≈10.5 °C at 0.020 kg. s −1 , which is ≈ 4.8 % higher than DI water. Further, CuO nanofluids reduced the average surface temperature of PV cell by 5.67 °C over standalone PV system. In tested SBS-PV/T system, an average electrical efficiency dropped from 9.97 % to 9.52 % with CuO nanofluids against 11 % of stand-alone PV system. The tested SBS-PV/T system achieved the highest overall thermal efficiency ≈ 38.40 % with CuO nanofluids at an optimum mass flow rate of 0.035 kg. s −1 . Further, the economic analysis predicted a unit energy cost of about 3.39 INR/kWh for full-scale SBS-PV/T system, whereas, a stand-alone PV system cost about 4.26 INR/kWh.