Optimization and design of a hybrid solar-diesel-hydrogen system for sustainable RO desalination using an advanced dynamic metaheuristic algorithm

Water and electricity supply to remote areas through reverse osmosis (RO) desalination units powered by renewable energy is essential for sustainable development. This paper presents three advanced dynamic metaheuristic algorithms for the optimal design and long-term capacity planning of standalone hybrid systems comprising photovoltaics, electrolyzers, fuel cells, diesel generators, hydrogen storage tanks, and RO units. A novel Hybrid Cycle Charging/Load Following (HCC-LF) dispatch strategy is introduced, which switches between Cycle Charging and Load Following according to the hydrogen-storage state of charge. The optimization framework aims to minimize total cost and carbon emissions while maximizing system reliability and renewable-energy utilization. The proposed methods are compared with Harmony Search (HS), Global Dynamic HS, and Simulated Annealing under multiple operating and policy scenarios. The results show that the proposed algorithms, combined with the HCC-LF strategy, achieve lower cost, reduced emissions, and improved reliability than the conventional approaches.