Design, testing and evaluation of a community hydrogen storage system for end user applications

• A H2 storage installation was integrated in a microgrid for a low carbon community.
• The system performs PV energy time-shift and demand load shifting simultaneously.
• The round trip efficiency of the system was 0.52.
• The performance of a 4 kg magnesium hydride storage tank is analysed.
• H2 flexibility and capacity for mid and long-term energy storage is demonstrated.

A hydrogen community energy storage (H-CES) system including a PEM electrolyser, metal hydride tank and PEMFC unit was designed, built and tested for a low carbon community. The H-CES performs end user applications including PV energy time-shift and demand load shifting. The system proved to have good flexibility and capability for mid-term and long term energy storage, with a round trip efficiency of 52%. Mid-term energy storage was demonstrated when the H-CES performed demand load shifting and hydrogen was stored for use one day later. Additionally, when PV energy time-shift was added to demand load shifting the operational hours of the electrolyser increased by 116%. Some improvements for future H-CES systems are also discussed in this study, the consideration of the optimum electronic equipment for the technology and rating being considered a key factor to maximize the discharge rating, round trip efficiency and reliability.