Exergy and Economic Analysis of Water-to-Grid Supply Chain of Hydrogen Using the Physical and Chemical Storage System

A sustainable hydrogen economy requires effective storage and transportation strategies, alongside advanced production technologies. The traditional physical hydrogen storage often incurs significant losses and additional equipment costs, while material-based methods need additional supply of energy for dehydrogenation reactions. This study evaluates the exergy and economic performance of both approaches within a defined supply chain. High-pressure hydrogen storage is relatively simple but suffers considerable exergy losses during compression. In contrast, the liquid organic hydrogen carrier (LOHC) system offers advantages in both efficiency and economic feasibility. By thermally integrating LOHC dehydrogenation with fuel cell reactions, the overall system efficiency increases by about 6%, achieving 2% higher exergy efficiency compared to high-pressure storage. Moreover, the LOHC materials share properties with conventional fuels, providing economic benefits for long-distance transport and allowing the use of existing oil infrastructure. These findings suggest that LOHC-based storage is a viable option for large-scale hydrogen supply systems.