Renewable energy introduces (seasonal) imbalances between the supply and demand, contributing to net congestion on the electric grid. Seasonal energy storage offers a potential solution by shifting excess renewable generation to periods of shortage. This research investigates the feasibility of using room temperature metal hydrides for seasonal energy storage in the built environment, the pilot: Urban Energy Island project of the housing corporation deltaWonen as a case study. 40 apartments will be part of an innovative energy system to become 80\% autarkic while being limited to 40 kW of available grid capacity.
To evaluate this concept, a system-level model predictive control (MPC) strategy was developed to coordinate the energy supply and demand across a daily battery, the electric grid capacity, a PEM electrolyser, and a PEM fuel cell, interconnected via a TiFe metal hydride storage system. Waste heat from the different components is also recovered and utilised. After calibrating with ten-year average data and verifying using verification tests, the model was tested for the years 2013 and 2015, including extreme cases. Beyond technical performance, the research also asses safety, cost, reliability, environmental impact and spatial feasibility.
The results show that while the current size of the metal hydrate storage is insufficient to cover the seasonal energy demand, it is effective in supporting shorter-term shortages, such as during a dunkelflaute. The system also shows potential for modular scaling. Future research should explore integrating dynamic energy grid prices into the MPC formulation and implementing a higher-level control layer for strategic long-term energy planning.