Feasibility study of a metal hydride hydrogen store for a self-sufficient solar hydrogen energy system

Abstract

The feasibility of using metal hydride hydrogen storage in a self-sufficient solar hydrogen energy system is studied. Several potential commercial and non-commercial metal hydrides are considered to find a material having a low Δ H value, a low hysteresis effect, gentle P- C- T, plateau slopes and a high hydrogen storage capacity. A 1 N m 3 metal hydride container employing a commercial Hydralloy C15 metal hydride with the proper P- C- T curves is analysed in more detail. As the thermal behaviour of the container is crucial in our application, steady-state and time-dependent thermal properties of the container are measured and the respective models are derived. The metal hydride container is also tested under realistic conditions to get further operational experience on its technical feasibility. Based on this study, low-temperature metal hydrides seem to be technically and economically feasible for small-scale self-sufficient solar hydrogen systems in which high volumetric energy density is needed due to limited space.