The use of renewable energy sources such as solar cell array, wind turbines and fuel cells has dramatically increased over the last decade. Growing cost of and potential depletion of fossil fuels, ozone pollution, global warming, and strict environmental laws have led to the generation of electrical energy from renewable energy sources by many countries. Today, the use of solar power is one of the world's most abundant and powerful sources of renewable energy to meet the increasing demand for electricity. A detailed mathematical model is an important resource for researchers to understand the features, assess the efficiency of photovoltaic systems and thus to optimize them.