The present study investigates the effect of nanofluids on a Photovolatic thermal solar system experimentally. Three different nanofluids MWCNT, Al2O3, and TiO2 are considered to act as a coolant to reduce the PV panel temperature at constant volume ratio of 0.3%. A parametric analysis had been carried out in outdoor conditions for measuring the energy and exergy efficiency of the system. In addition to the above, the effect of nanofluids mass flow rate on thermal efficiency and PV temperature was studied. The nanoparticles were dispersed evenly by using ultrasonication process and it was ensured that there were zero deposits. However, the addition of the nanofluids alters the thermophysical properties of the base fluid. By analyzing the experimental results, it is found that, the addition of nanofluids showed profound results in electrical output, thermal efficiency and overall efficiency. Besides that, all results highly depend on the solar irradiance. All nanofluids MWCNT, Al2O3, and TiO2 showed potential results by reporting 45%, 36% and 25% increase in electrical power and 47%, 33% and 27% improvement in electrical efficiency respectively. Moreover, MWCNT reported the superior thermal conductivity and better physical properties than water, Al2O3, and TiO2. The highest thermal exergy efficiency and overall exergy, hydrogen production were found for MWCNT based PV/T system. Furthermore, from the obtained results, it is evident that the efficiency of the system can be enhanced by improving the mass flow rate of the nanofluids. © 2020 Elsevier Ltd