Experimental analysis of AB₂ metal hydride storage in PEM power-to-hydrogen systems: Integration and energy trade-offs

The integration of hydrogen storage into renewable energy systems demands diversified technological solutions to address the inherent intermittency of renewable power. In this context, low-pressure metal hydride (MH) systems offer a compelling alternative to high-pressure hydrogen storage systems, particularly in applications with stringent safety requirements or spatial limitations. Their reversible absorption characteristics and solid-state storage capabilities position them as a valuable option within the broader hydrogen storage landscape. This study presents experimental results and an energy-focused analysis evaluating the thermodynamic behavior and efficiency of MH-based storage modules operating within a Power-to-Gas configuration. The work investigates how pressure and thermal management affect the trade-off between energy efficiency and renewable energy utilization. Findings indicate that operation at 15 bar with passive thermal regulation (20 °C without active cooling) enables high hydrogen uptake, limits energy losses, and ensures a balanced system response. This configuration proves especially relevant in real-world scenarios prioritizing safety, simplicity, and renewable energy absorption.