Feasibility study of renewable energy resources and optimization of electrical hybrid energy systems: Case study for Islamic Azad University, South Tehran Branch, Iran

Renewable energies are increasingly seen as the best solution to a growing global population demanding affordable access to electricity while reducing the need for fossil fuels. Country of Iran has vast untapped solar, wind, geothermal and hydroelectric sources that hold the potential to meet domestic needs. Renewable energy is also essential to Iran as it will curb massive air pollution. In this paper economical and feasibility study of various hybrid systems are performed by using HOMER software model for supplying electricity to the Engineering Department of Islamic Azad University. For this study, annual electricity demand of the university is 1,174,935 kWh with a peak demand of about 331 kW, average wind speeds, based on hourly data during the period of eleven years (2000-2010), are between 3 to 5 m/s in all months of the year. For solar radiation, six models are evaluated to select the best model for estimation of the daily global solar radiation (GSR) on a horizontal surface in the study location. Among these six models, H/HO=a+b (S/S0)+ c(S/S0)2 is chosen as the most optimum model for estimating solar irradiation. The results indicate that among the three hybrid systems for fulfilling electrical energy needs, the Wind/Diesel/Battery hybrid system with 9 wind turbines (20 kW), one diesel generator (300 kW), 50 batteries, and 50 kW power converters with net present cost of $4,281,800 and cost of energy of 0.285 $/kWh is the most economically efficient hybrid system. (based on 2015 US dollar)