Experimental and numerical study of photovoltaic performance integrated with a nanofluid-based optical filter and a compound parabolic concentrator

•A liquid filter PV/T system with a compound parabolic concentrator is investigated.•From 1 cm to 2 cm in thickness, the power growth rate rose from 37.8% to 102%.•From 1 cm to 2 cm in thickness, the efficiency growth rate went from 87.8% to 131%.•From a concentration of 0 to 200 ppm, the power growth rate rose from 37.8% to 93%.•When the concentration reached 200 ppm, the efficiency rose to a maximum of 107.5%. To avoid photovoltaic cells’ overheating and to reduce their performance, the solarspectrum can be separated into two portions using the spectral splitting process. The first part is immediately transformed into electricity, while the second is used to produce heat energy. The system described in this paper combines a compound parabolic concentrator (CPC) with a ZnO-water nanofluid that flows over the PV cell and serves as a selective absorptive filter. Several tests were run on different days to determine how water thicknesses of 1, 1.5, and 2 cm affected the system's performance. The system's performance was then examined in other tests to see how various ZnO-water nanofluid concentrations of 50, 100, 150, and 200 ppm affected it. Moreover, a transient numerical model was also offered to utilize the MATLAB program to compare the expected instantaneous and average electric and thermal performances with the experimental results. According to experimental results, electrical power, and efficiency enhancement percentages climb gradually with thickness, from 37.8% and 87.8% at 1 cm to 102% and 130.9% at 2 cm, respectively. As concentration increases, enhancement percentages rise steadily, from 37.8% and 87.8% at 0 ppm to 93% and 107.5% at 200 ppm, respectively. Furthermore, the experiment's findings show that all filtered cells are more electrically efficient than no-filter cells, with electrical efficiency increasing continuously from 6.2% at a thickness of 1 cm to 7.9% at 2 cm. In comparison, it gradually increases from 6.2% at 0 ppm to 7.7% at 100 ppm before dropping to 6.2% at 200 ppm. Additionally, as the channel thickness rises from 1 cm to 2 cm, the thermal and total efficiencies improve gradually, from 21.5 and 30.3% to 41.3 and 45.2%, respectively. At the same time, concentration causes them to grow steadily, from 21.5 and 30.3% at 0 ppm to 31.4 and 34.6% at 200 ppm. Theoretical results support the trend of a progressive climb in electrical power and efficiency enhancement percentages by increasing the channel thickness or raising the concent