Optimum Design of a Solar-Wind-Diesel Hybrid Energy System with Multiple Types of Storage Devices Driving a Reverse Osmosis Desalination Process

To simultaneously satisfy the electricity and freshwater requirements, a superstructure of a solar-wind-diesel hybrid energy system (HES) with multiple types of storage devices driving a reverse osmosis desalination (ROD) process is established in this paper. The corresponding mathematical model of the HES, potentially including photovoltaic cells, a wind turbine, a diesel generator, a ROD unit, different battery storage technologies, or a water tank is developed and features mixed integer linear programming. The optimum design and operation schemes of the HES can be obtained by taking the minimum total annual cost as the optimization objective. To verify the effectiveness of the proposed method, an example of a solar-wind-diesel system for supplying a ROD process in Saudi Arabia is adopted. The results show that a photovoltaic panel, wind turbine, diesel generator, lead-acid battery, Li-ion battery and water tank are selected in the HES with the minimum total annual cost (i.e., 1.16 x 10(5) USD.y(-1)), by satisfying the requirement of the renewable energy penetration rate (i.e., 0.8). Then, a quantified method is proposed to determine the optimal design and operation schemes of the HES, including both economic and environmental aspects. Finally, the HES with various generators and multiple types of storage devices shows a better performance in terms of economy and renewable energy utilization.