The concept of concentrating solar photovoltaic energy has gained a lot of traction in recent years. In this paper, a design model for a concentrator photovoltaic parabolic dish with multi-junction solar cells is theoretically analyzed by using equations which are simulated in the MATLAB program under the effect of concentrator radius during one month (June) for rim angles of 55o, 65o, 75o, and 85o, during six months at rim angle 55o, and for 12 months with rim angles of 55o, 65o, 75o, and 85o and a radius of (0.25m). The efficiency of the system has been calculated. The findings revealed that the concentration ratio increases as the concentrator’s radius increases. The best value of the concentration ratio is 4500 at rim angle 55° and a radius of 1 m, which gives an input power 39 times higher than the input power at rim angle 85° in June. The input power increases as the radius of the concentrator increases, and it is valued about 310 W in January and becomes 385 W in May, which is 1.2 times higher in comparison to the other. The best value of input power for rim angle 55o and radius of 0.25m is (24 W) in May, which gives output power of 9.5W.

Photovoltaic concentrating systems have recently become one of the topics of interest to researchers around the world due to the high cost of semiconductors used in the manufacture of solar cells, as well as the wide area of traditional photovoltaic panels. The target can be met by compensating for the vast areas of solar cells with smaller cell areas made of reflective or refractive materials that concentrate higher intensity solar radiation to reach a higher outward power. In this research a parabolic dish solar photovoltaic concentrator is studied theoretically. The concentration ratio at the reflecting concentrator has been studied as a function of reflectance and shading losses under five different rim angles ( 45°, 55°, 65°,75° and 85°) using equations simulated in the MATLAB software. Following that, the total absorbed solar radiation and output power provided by CPV with multi-junction solar cells. the results indicated that the concentration ratio increase linearly with reflectance, while it increases as the rim angle decrease. The best value of concentration ratio is about 172 for rim angle 45° and reflectance 95%.