Battery versus hydrogen storage for renewable-powered RO desalination: A technoeconomic and environmental analysis in coastal Saudi Arabia

This study presents a comprehensive and systematic assessment comparing battery and hydrogen energy storage systems for powering reverse osmosis (RO) desalination. The research introduces a multi-scenario optimization framework applied to ten coastal locations in Saudi Arabia, encompassing photovoltaic (PV), wind turbine (WT), hybrid PV/WT, and PV/WT/diesel configurations, each integrated with either battery or hydrogen storage. System optimization using the Artificial Rabbit Optimization (ARO) algorithm for a four-stage RO unit reduced energy demand by approximately 41 % relative to a single-stage design. Two optimization modes were employed: a single-objective formulation minimizing the Levelized Cost of Water (LCOW) and a multi-objective formulation minimizing both LCOW and Annual Carbon Emissions (ACE). Battery storage proved most cost-effective, achieving an LCOW of 1.66 $/m³ in PV-powered systems, whereas hydrogen storage minimized ACE to 10 tons/year in wind-powered configurations. No configuration was universally optimal, underscoring trade-offs between economic and environmental objectives.