Techno-Economic Analysis and Optimization of an Off-Grid Hybrid Photovoltaic–Diesel–Battery System: Effect of Solar Tracker

Abstract

Increment in energy demand, limitation of fossil fuels and fluctuations in their price, in addition to their pollution, necessitate development of renewable energy systems. Regarding the considerable potential of solar energy in Iran, this type of renewable energy has developed more compared with other renewable energies. Hybrid technologies consisting of photovoltaic (PV) cells, diesel generator, and battery are one of the efficient solutions to resolve the issues related to the energy supply of rural areas. In this study, a hybrid PV/diesel/battery system composed of the mentioned components is applied to supply the off-grid power with capacity of 233.10 kWh/day with peak load of 38.38 kW in a rural region in South Khorasan, Iran. The purpose of this study is to reduce the net present cost (NPC), levelized cost of energy (LCOE), CO2 reduction, renewable fraction (RF) enhancement and increase reliability. In order to improve the performance of the system, different tracking system, including fixed system, horizontal axis with monthly and continuous adjustment, vertical axis with continuous adjustment and two-axis tracker, are analyzed and assessed. The results indicate that the vertical axis with continuous adjustment tracker is the most suitable option in terms of economic and technical requirements. In this work, a sensitivity analysis is performed on different parameters such as PV cost, interest rate, diesel generator cost, battery cost, and price of fuel, and the outcomes reveal that the hybrid system with vertical axis continuous adjustment is very sensitive to costs of fuel and the battery, i.e., NPC decreases by 5% in case of 20% variations in costs of battery and fuel. In addition, it is found that diesel generator and inverter costs significantly influence NPC of the system.