Economic Evaluation of Solar Electricity (Photovoltaic) Based on the Space Available in the Building in Different Climates of Iran

Solar energy is one of the most significant types of renewable energy needed for development. Increasing population and area of land occupation and economic problems in construction of power plants are the main obstacles to the wide solar electricity production. The main aim in this research has been the design and evaluation of home photovoltaic power plants connected to the network on roofs of buildings.  Doing so, we have used three different climate conditions; regions of cold and mountainous climate (Tabriz), mild and humid (Sari) and warm and dry (Semnan) with COM FAR software. Concerning the design principles, climatic factors such as the effect of temperature rise on the panel surface, the effect of air pollution and the average temperature of the city along with the amount of sunshine were applied. The applied discount rate was 17.3 % and the inflation rate was 20.7 %.  Semnan, with an internal return rate of 32.13%, provides the largest economic yield and Sari with a higher average temperature than Tabriz city is the lowest return city. The return period of normal capital is sixth year. The net return period is Semnan, the ninth, but Tabriz and Sari in the tenth year. In the analysis of sensitivity to increase the rate of internal efficiency, the effect of fixed costs reduction (including the cost of purchase equipment) is more dominant than the increase in the price of photovoltaic electricity. Therefore, the expansion of solar power generation requires extensive support.