Feasibility evaluation of hydrogen as seasonal energy storage for energy-neutral neighborhoods

he decarbonization of the European Union energy sector is associated with large-scale integration of renewable energy sources (RES) and a transition toward decentralized electricity supply architectures. While residential energy storage systems (ESS) based on electrochemical batteries enable short-term balancing of renewable generation, their limited energy capacity and high cost make them unsuitable for seasonal energy storage, leading to significant curtailment of renewable energy production. Hydrogen-based energy storage is considered a promising alternative due to its high specific energy capacity and suitability for long-term storage, despite low round-trip electrical efficiency and infrastructural challenges. This paper evaluates the feasibility of hydrogen technologies for electrical energy storage in RES-based residential power systems in Estonia. The analysis is based on a real Estonian household dataset and considers metrics such as near-zero energy consumption, grid-support capability, and RES energy utilization. A comparative assessment of daily and seasonal ESS configur ations together with a techno-economic comparison of battery and hydrogen-based storage systems is performed. Special attention is given to the utilization of waste heat generated during hydrogen-to-electricity conversion for residential heating, which is identified as a key condition for achieving economic feasibility and improving overall system efficiency.