Increasing hydrogen energy efficiency by heat integration between fuel cell, hydride tank and electrolyzer

Chemical processes offer untapped potential to increase overall system efficiencies by synergizing renewable hydrogen storage with dispatchable renewable energy facilities. In this study an Energy Storage Facility model is developed and simulation conducted to examine this potential. The model incorporates a Solid Oxide Fuel Cell (SOFC) integrated with a Magnesium Hydride (MgH
₂
) Tank and an alkaline electrolyzer linked to the power grid. Surplus grid power is converted to hydrogen and stored as magnesium hydride. This storage process generates waste heat which is used to partially offset the water heating requirement of the electrolyzer. Simulation results demonstrate 20% reduction in parasitic heat energy consumption using this waste heat. Stored hydrogen provides power on demand via the SOFC. Waste heat from SOFC fulfils the desorption heat demand of the MgH
₂
Tank. Simulation results reveal waste heat from the SOFC is just enough to preheat oxygen and hydrogen and desorb hydrogen from the MgH
₂
tank. These results are encouraging, warranting further investigation into metal hydride storage to help Australia's transition towards renewable energy resources.