PERFORMANCE ANALYSIS OF PHOTOVOLTAIC THERMAL (PVT) SYSTEMS EMPLOYING GRAPHENE NANOPLATELETS (GNP) STABILIZED WITH POLYVINYLPYRROLIDONE (PVP)

Photovoltaic thermal (PVT) systems are gaining attention for their ability to generate both electricity and heat simultaneously. However, overheating in conventional systems reduces their efficiency. This study investigates the enhancement of PVT performance using nanofluids formulated with graphene nanoplatelets (GNP) and polyvinylpyrrolidone (PVP) as a surfactant. Nanofluids were prepared via a two-step method with varying GNP concentrations (0.2–1.0 wt.%) and PVP ratios (40% of GNP weight). An indoor experimental setup using a monocrystalline PV module with copper serpentine piping was tested under simulated solar irradiance levels ranging from 200 W/m² to 800 W/m² under 3 LPM flowrate. Thermal and electrical efficiencies were evaluated, supported by uniformity, temporal, and spectral assessments to ensure simulation accuracy. Results showed that GNP-based nanofluids significantly improved heat dissipation and enhanced overall PVT performance compared to distilled water. Optimal nanoparticle concentrations maintained stability without causing excessive pressure drops. In conclusion, the integration of GNP nanofluids with PVP surfactant offers a promising approach to improving the thermal regulation and efficiency of PVT systems, supporting advancements in renewable energy technologies. Include conclusion with results. The system achieved a maximum thermal efficiency, ηth of 86.62% ± 7.71% and an electrical efficiency, ηel of 9.57% ± 0.31%.