Optimal planning of hybrid renewable energy system considering virtual energy storage of desalination plant based on mixed-integer NSGA-III

Due to the shortage of freshwater and energy crisis, seawater desalination with renewable energy has been proposed. A method for determining optimal planning of coastal hybrid renewable energy system (HRES) is proposed in this paper. Firstly, the system composition is introduced, and the virtual energy storage (VES) characteristics of the seawater reverse osmosis desalination plant is utilized to accommodate renewable energy generation. In order to reduce the system total cost, demand side management (DSM) measures are designed and applied to the regular electric load in the system. The methodology for planning optimization of the system is suggested, with objectives aiming at minimizing system total cost, end-user satisfaction loss caused by DSM, and tie-line power fluctuation. Since the problem has a mixed-integer manner, a modification of Non-dominated Sorting Genetic Algorithm-III (NSGA-III) is proposed. The newly-developed NSGA-III variant, named as MINSGA-III, is capable of solving mixed-integer optimization problem in an evolutionary algorithm fashion. This paper also presents several case studies to verify the feasibility and merits of the proposed method. The simulation results show that the proposed method is effective and feasible, and both DSM measures and VES approach have positive impact on the system modelling. The proposed MINSGA-III can effectively determine the solution of the multi-objective optimization problem.