Comprehensive Design of Hydrogen-Battery Hybrid Energy Storage System in Green Methanol Production from Economic, Safety, and Resilience Perspectives

This study proposes a multiobjective optimization for a hybrid hydrogen-battery energy storage system based on hierarchical control and flexible integration for green methanol processes. The optimized energy management strategy aims to comprehensively enhance the economic viability, safety, and resilience of the hybrid system. The optimal solution was identified by nondominated sorting genetic algorithm II (NSGA-II) and the method of criteria importance through intercriteria correlation with the technique for order preference by similarity to ideal solution (CRITIC-TOPSIS), with the levelized cost of electricity and hydrogen demand of methanol at $4.13/kg, the average lethal radius of hydrogen tank at 101.85m, and the ratio of flexible time at 0.776. The superior economic performance of the hydrogen storage system underscores its dominant role in the hybrid system. The battery subsystem has a minor impact on reducing the hydrogen storage capacity. The power cost of high-pressure hydrogen compression significantly outweighs cost reduction in hydrogen storage. A substantial investment of 82.8% in the hybrid storage system poses significant constraints on economic feasibility. Reducing hydrogen storage is the primary approach to addressing challenges in existing off-grid hydrogen storage systems. Valuable suggestions to enhance system economics include implementing flexible methanol load variations and selecting appropriate energy-saving measures in high-pressure hydrogen storage systems. Furthermore, several policy suggestions are proposed for the development of sustainable energy systems in the future.