“In recent years, due to the energy crisis and fossil and nuclear problems, extensive research has been done on renewable energies in the world. The need for energy resources is a fundamental issue in human life. Researchers have been forced to explore high efficiency technologies to convert different types of energy into electrical energy, due to increasing need for energy, limited fossil fuel resources and increasing environmental pollution. The present educational booklet in 2018 has been compiled by renewable energy discipline of Tarh O Palayesh Engineering Company, in order to acquaint with photovoltaic systems as one of the most important of renewable energy technologies.”