Experimental-Numerical Investigation of the Photovoltaic Thermal System with Polypropylene Heat Exchanger: Case in Morocco

Abstract

This study uses experimental and numerical methods to evaluate a hybrid photovoltaic-thermal system (PVT-S) against a traditional photovoltaic panel (PV-P) in El Jadida, Morocco. A polypropylene heat exchanger covering 70% of the PV-P surface is analyzed for its impact on thermal distribution and performance. The effects of water mass flow rate (FRT) and solar irradiance on cell temperature, electrical power, thermal energy, and efficiencies are examined. Simulations were performed using the finite element method for water FRT of 60, 90, 120, and 180 L/h. Experimental tests validated the numerical results, showing strong agreement and confirming the analyses' reliability. The results reveal a maximum power difference of 30.42 W between the PVT-S and PV-P at 120 L/h FRT. Thermal and electrical efficiencies and system power increase with higher flow rates, greater solar irradiation, and a smaller inlet-outlet temperature difference. A higher FRT results in a lower cell temperature. The average thermal efficiency of the PVT system, between 32.99% and 51.15%, is lower than literature values due to imperfect thermal contact between the polypropylene heat exchanger and the PV-P, along with a limited irrigated surface area of 70%. Partial cooling leads to uneven thermal distribution, reducing performance and shortening solar cell lifespan.