Construction and operation of hydrogen energy utilization system for a zero emission building

Abstract A bench-scale stationary hydrogen energy utilization system with renewable energy (RE) that realizes a zero emission building (ZEB) is presented. To facilitate compactness, safety, and mild operation conditions, a polymer electrolyte membrane (PEM) electrolyzer for hydrogen production (5 Nm3/h), PEM fuel cells (FC) for hydrogen use (3.5 kW), and metal hydride (MH) tanks for hydrogen storage (80 Nm3) are incorporated. Each hydrogen apparatus and Li-ion batteries (20 kW/20 kWh) are installed in a 12-ft. container and 20-kW photovoltaic panels provide power. A building energy management system (BEMS) controlled these system components in an integrated manner. The PEM Ely and FC have fast start-up and high efficiency under partial load operations, indicating suitability for daily start-stop operations. An AB-type TiFe-based alloy (520 kg) is used as the MH (not an AB5-type rare earth alloy that has been commonly used in bench-scale hydrogen store) because, in addition to being low-cost, it is non-hazardous material under Japanese regulations. The results of a 24-h operation experiment verify ZEB attainment. PEM FC and TiFe-based tanks thermal integration results indicate that hydrogen use operation is achievable without external heat sources.