Climate change is one of the biggest environmental, political, economic, technological, and social challenges of the 21st century. Due to ever-increasing fossil fuels costs. The world energy system should be transitioned to renewable energy sources to mitigate greenhouse gas emissions. Solar energy is one of the suitable alternatives to fossil fuel usage. Currently, the most widely available solar technologies are solar photovoltaic (PV) and solar thermal. The integration of these two techniques enables the exploitation of the most significant amount of solar radiation. This combination has led to a hybrid photovoltaic/thermal system (PV/T). Concentrated solar radiation on PV cells, known as concentrated photovoltaic (CPV), effectively decreases PV receivers’ area and harnesses the same quantity of solar radiation. However, the main problem with CPV is the elevated PV surface temperature, which often requires active cooling. This issue can be solved by introducing a Concentrating Photovoltaic Thermal (CPVT) system. In this article, a new CPVT hybrid system based on Point Focus Fresnel Lens (PFFL) and embedded Multi Junction Photovoltaic (MJPV) (GaInP/InGaAs/Ge) cells has been experimentally investigated and numerically modelled under indoor conditions. Experiments and simulations were carried out at different heat transfer fluid (HTF) flow rates and under constant irradiation emitted from a sun simulator. The results indicate that the thermal and electrical performance of the CPVT system improves under the testing conditions, where the total efficiency was 68.7% and 73.5% for the experimental and CFD models, respectively. At the same time, the highest thermal efficiency of the experimental and CFD models was 49.5% and 55.4%, respectively. In contrast, the highest electrical efficiency was 36.5% and 37.1%. Therefore, the CPVT system has an excellent possibility of being competitive with conventional power generation systems.

Concentrated Photovoltaic Thermal (CPVT) systems play an important role in solar system development, reducing dependency on fossil fuels and meeting global energy demand. This research investigates the CPVT model, which uses pointfocus Fresnel lenses (PFFL) to amplify a significant amount of irradiance and focus it on photovoltaic surfaces to simultaneously produce electrical and thermal energy. The proposed model has Multi-Junction Photovoltaic (MJPV) solar cells, PFFL, copper heat sinks, and a copper cooling pipe. A numerical model was developed to investigate and evaluate the thermal and electrical performance of the proposed model under various input and output parameters. The numerical model has been first validated and then used to simulate the impact of the concentration ratio (CR), Heat transfer fluid (HTF) flow rates, HTF inlet temperature, incident radiation, and the optical efficiency of the Fresnel lens on the HTF outlet temperature, MJPV cell temperature, and thermal and electrical efficiency. The CFD model's minimum and maximum thermal output efficiencies were around 59.5% and 85.3%, respectively. The highest electrical efficiency occurred at a mass flow rate of 0.025 kg/s, CR = 100x, and its value was 35.74%. Further, the results show that the maximum thermal and electrical energies were 618.5 W and 219.35 W, respectively. The numerical model was validated with experimental data and demonstrated that the maximum error between the experimental and CFD models was less than 5%, confirming that the results are satisfactory and agree well with the experimental results. Finally, the results show that CPVT is a promising renewable energy system with excellent opportunities to compete with conventional power generation systems.

Concentrated Photovoltaic Thermal (CPVT) systems are a hybrid of concentrated photovoltaic (CPV) and photovoltaic thermal (PVT) systems that use optics such as lenses to concentrate a significant amount of sunlight onto photovoltaic surfaces to produce electrical and thermal energy simultaneously. The CPVT model equipped with MJPV (InGaP/InGaAs/Ge) solar cells, point-focus Fresnel lenses, heat sinks, and a cooling pipe has been numerically investigated. A numerical model was developed to investigate and evaluate the thermal and electrical performance of the proposed model under various input and output parameters. The inputs consisted of HTF flow rates, HTF inlet temperature, incident radiation, concentration ratio, and the optical efficiency of the Fresnel lens. In contrast, the outputs consisted of the HTF outlet temperature, MJPV cell temperature, and thermal and electrical efficiency. The results show that the highest thermal and electrical efficiencies occurred at a mass flow rate of 0.025 kg/s, and their values were 85.31% and 35.74%, respectively. The results also demonstrate that concentration ratio affects the electrical characteristics. Finally, the results indicated that CPVT is a promising renewable energy system and has an excellent possibility of being competitive with conventional power generation systems.