Today, electricity has become an essential part of the life. At present, a large part of the electricity is supplied by thermal power plants and hydropower plants. With increasing concerns about greenhouse gas emissions and other environmental issues new technologies such as using solar energy for electricity generation are recommended. In this paper, a typical 500-kilowatt solar power plant connected to the grid is evaluated. Simulations are implemented by PVsyst software and its performance on different climatic conditions is investigated. Moreover, the performance ratio and different types of energy losses (such as losses due to temperature increases, the domestic network losses, losses of power electronics (convertors)) are calculated. Finally, the amount of energy produced and injected into the network and the annual income from the construction to the south of Tehran, Kerman and Yazd are compared. Results show that the city of Yazd as a suitable site for the construction of the plant is the best alternative among other two options.