A comprehensive experimental study of cooling photovoltaic panels using phase change materials under free and forced convection – Experiments and transient analysis

Abstract

Solar radiation is captured by photovoltaic (PV) panels, which use it to create electricity. However, an overabundance of photons striking the PV's surface raises its temperature, which lowers its efficiency. These days, cooling solar panels is very important, and research on these methods is widely available in the literature. Thus, the study field's problems truly lie in developing new or improved methods for doing the same tasks. The goal of this work is to further boost the efficiency of photovoltaic (PV) panels beyond what can be achieved with PCM and free/forced convection alone. To do this, phase change materials (PCM) are cooled using both free and forced convection. In accordance with the latitude of Lebanon's Bekaa Valley, four cooling techniques are experimentally investigated. A photovoltaic panel using phase-change material (PCM) with copper and aluminum wires in a 70 %–20 %–10 % mass ratio (CPCM-PV), respectively, is the first cooling method. In the second approach, four 5 cm long fins are fixed under free convection using the same combination of aluminum fins inside the PCM container while preserving the same ratio (IEF-PCM-Free-PV). The third technique is the same as the second but with forced convection (IEF-PCM-Forced-PV), while the fourth technique uses an aluminum finned plate with 16 finned plates under forced convection (F-Forced-PV). IEF-PCM-Forced-PV showed the most relative increases in efficiency rate of energy dissipated of 20.36 % and 62.24 %, respectively, as compared to the regular PV panel, according to the results. F-Forced-PV, IEF-PCM-Free-PV, and CPCM-PV showed an increase in relative efficiency of 16.87 %, 6.3 %, and 3.9 % respectively, and correspondingly, these enhancements were accompanied by an increase in energy dissipation of 55.80 %, 44.85 %, and 41.18 % for each system. Economically, the IEF-PCM-Forced-PV had the highest total yearly savings of $17.87 with a payback period of 1.9 years. An appropriate transient energy balance is conducted and permitted to demonstrate clearly the transient behavior of the system under the various cooling techniques. Finally, the percentage of enhancement using the newly suggested composite PCM with internal and external fins under forced convection is compared to the enhancement found in the literature for various classical techniques and shows greater potential for further enhancement of the PV performance.