One of the essential factors which must be considered in the design and employment of photovoltaic system is the Solar radiation. The effectiveness of the PV system is improved and at the same time the expense of electricity generation is decreased by using concentration photovoltaic. A V-trough integrated with low concentration PV system was utilized (LCPV) to get this aim. To improve the amount of absorbed radiation, optical modelling Of V-trough was performed. Mathematical model for estimation of solar radiation is showed in this research. The beginning point is demonstrated by the mathematical model of extraterrestrial radiation, producing eventually in the model for solar radiation, absorbed by a low concentration photovoltaic panel. Positions of reflectors has been modified and optimal position of reflectors has been determined by both experimental measures and numerical calculations to get superior concentration of solar radiation intensity. The calculated values have been discovered to be in good coincidence with the measured ones, both leading to the optimal position of the flat reflector to be α1 = 35° (angle of lower reflector with horizontal) and α2= 5 ~ 15° (angle of upper reflector with vertical). These assessment models for solar radiation have been specialized located in the 6th October city, Egypt, and have been proved by numerical simulation. In this research, a comparative analysis was also performed with respect to the solar irradiation absorbed by the PV panels with solar radiation and without concentration absorbed by a low concentration photovoltaic panel. This analysis was depending on the output of numerical simulation and experimental trials.