In this experimental investigation, an effort is executed to evaluate and compare the energetic and exergetic performances of three nanofluid-based photovoltaic/thermal (PVT) systems, namely a PVT system with a sheetand- serpentine tube collector (case-I), a PVT system with a sheet-and-grooved serpentine tube type collector with a groove pitch of 8 mm (case-II), and a PVT system with a sheet-and-grooved serpentine tube type collector with a groove pitch of 5.4 mm (case-III). The water-Fe3O4 nanofluid was considered as the working fluid. The influences of nanoadditive concentration (Ø) (0–1%) and flow rate (mf) of nanofluid (10–40 kg/h) on the performance features were then examined. It was found that at any given Ø, the overall energy, overall exergy, and electrical performances of the case-I, II, and II improved with an increase in nanofluid mf (10–40 kg/h) and vice versa. Thus, the case-III yielded 15% and 6% better overall energy efficiency, 4.6% and 2.3% better overall exergy efficiency, and 3.3% and 1.9% better electrical energy efficiency than the case-I and II at a Ø and nanofluid mf of 1.0% and 40 kg/h. The maximum electrical energy of case-I, II, and III is 9.5%, 11%, and 13.1% higher than those achieved by the PV panel in absence of cooling. The findings obtained from this study can be used to design photovoltaic systems with significant energetic and exergetic performance.
