Technoeconomic Insights into Metal Hydrides for Stationary Hydrogen Storage

Metal hydrides (MHs) are promising candidates for storing hydrogen at ambient conditions at high volumetric energy densities. Recent developments suggest hydride-based systems can cycle and operate at favorable pressures and temperatures that work well with fuel cells used in stationary power applications. In this study, we present a comprehensive design and cost analysis of MH-based long duration hydrogen storage facilities for a variety of power end users (0 to 20 megawatts (MW) supplied over 0 to 100 hours), to offer insights on technical targets for material development and operation strategies. Our findings indicate that hydride-based storage systems hold significant size advantage in physical footprint, requiring up to 65% less land than 170-bar compressed gas storage. Metal hydride systems can be cost competitive with 350-bar compressed gas systems, with TiFe_0.85Mn_0.05 achieving $0.45/kWh and complex MH Mg(NH₂)₂-2.1LiH-0.1KH achieving $0.38/kWh. Extending charging times and increasing operating cycles significantly reduce levelized cost of storage, especially for complex MHs. Key strategies to further enhance the competitiveness of MHs include leveraging waste heat from fuel cells, reducing use of critical minerals, and achieving MH production costs of US$10/kg.