Using renewable energy is one of the sustainable solutions to deal with the problems caused by the excessive use of fossil fuels. In recent years, the use of solar electricity has developed more than other methods of using renewable energy due to its applicability on a small to large scale. Solar panels, as part of solar power systems that convert solar radiant energy into electrical energy, are installed at an optimal angle to receive the most energy. The purpose of the present study is to study the effect of the refractive index of solar panel glass on the amount of energy received and its optimal angle. The results showed that increasing the refractive index of the glass coating of solar panels will cause a significant reduction in the annual energy received. The annual energy received for a panel installed at an angle of 20 degrees at a latitude of 30 degrees is about 12.591×109 W. Considering a refractive index of about 1.2, the energy received is reduced to 10.530×109 W (about 16.4%). A refractive index of 1.6 also causes a reduction of about 42.7% of the energy received. Considering an increase in the refractive index of 1.4 led to an increase of about 2 degrees in the optimal angle.
