Abstract
Photovoltaic (PV) systems are a very popular energy conversion system for electric energy supply due to their ease of connection and fast rate of conversion. However, a disadvantage of these systems is their low efficiency. Many techniques have been proposed to enhance the efficiency of PV systems. In this article, numerical and experimental studies were performed to test the effect of pyramidal transparent covers made of Perspex on the incident radiation reaching PV panels. The energy of light depends on the electric field, and the electric field depends on the permittivity. As the relative permittivity of Perspex is higher than the relative permittivity of air, the energy of the panel with the pyramidal Perspex cover is higher than the energy of the panel without pyramids. In addition, the total irradiance reaching the base of the pyramids was investigated in order to show the effect of the incidence angle on the computed irradiance. A 3D model was constructed and tested with different pyramidal cover dimensions and incidence angles. The tested dimensions were height to base length ratios of 1.5, 1.0, and 0.5. It was found that pyramidal covers with a height to base length ratio of 1.0 achieved the best performance of the three sizes. The simulation model was applied in order to study the solar radiation model for the solar panel with and without pyramids. Two parameters were studied in order to show the effect of the pyramidal covers on solar panel irradiance; these parameters used three different sizes of pyramids to study the effect of changing the incidence angle of the radiation source. The model was constructed in ANSYS-ICEM, then the mesh was exported to FLUENT 14.5. Moreover, the incident radiation on the panel for all tested incidence angles was found to be higher than for the panels without covers. In addition, the existence of the pyramidal cover was found to enhance the homogeneity of the distribution incident of rays on the PV panels. In the case of pyramids with R = 1, enhancement became clear at an incidence angle ranging from 69 degrees to 90 degrees, and the percentage increase in the energy fraction reached 0.2%.