Enhancing electric and thermal efficiency in solar photovoltaic thermal system using MWCNT-based water nanofluid with various surfactants

The study focuses on using nanofluids with multi-walled carbon nanotubes (MWCNTs) and different surfactants to determine the optimal cooling mixture. A mixture of 1000 ml distilled water and 0.1% MWCNTs with surfactants cetyl trimethyl ammonium bromide (CTAB), sodium dodecyl sulfate (SDS), and poly vinyl pyrrolidone (PVP) of 0.1% each was used. The PVT device was irradiated for 45 minutes with a light intensity of 1200 W/m2 to assess the thermal and electrical efficiency. The results indicate that the nanofluid with PVP has the highest thermal and electrical efficiency, followed by CTAB, no surfactant, SDS, and distilled water. The longer the irradiation time, the thermal efficiency tends to decrease due to less effective cooling, while the electrical efficiency increases. The increase is due to more photons being absorbed and the decrease is caused by the PVT surface becoming hot. It can be concluded that the addition of nanoparticles and surfactants to the base fluid can increase the efficiency of PVT. To increase the efficiency of PVT, nanofluids are needed that have high stability, high density, low viscosity, small specific heat, and high thermal conductivity.