Solar energy is used for domestic, industrial, and power plant consumption. From a nation-wide perspective, it has attracted increasing attention due to creating opportunities, reducing fossil fuels consumption, and also meeting the requirements for reduction of environmental pollutants. Given its geographical location which has endowed Iran with a desirable level of solar energy as a renewable source of energy, it is the first paper aimed to conduct a potentiometric study of constructing a 20 kW power plant in 31 capital cities in Iran, considering all the existing losses. PVsyst 6.7 and Meteonorm 7.1 software packages are used for analysis. Results showed that the required area for monocrystalline solar panels was less than that for polyc...