Economic dispatch optimization of a metal hydride storage system for supplying heat and electricity in a residential application

Abstract

To achieve affordable, clean energy, incorporating renewable energy into existing energy systems is the key. One challenge is the fluctuating nature of renewable resources, which can be asynchronous with energy demands. Hydrogen storage, particularly metal hydride storage, is a favorable solution for balancing supply and demand. In particular, metal hydride storage, compared with pressurized or liquefied hydrogen storage, is a favorable technology choice due to its storage energy density (50-100 kg H˙2/m³) and its low operating temperature and pressure. This paper presents a simulation-based framework to investigate the optimal design and operation of a coupled Electrolyzer-Fuel Cell-Metal Hydride system (SET-Unit) for minimizing operational and capital expenses in a residential application. The results show that integrating heat pumps with a metal-hydride storage system and photovoltaics can achieve 83% energy self-sufficiency and a 7.1-year payback period. Combining SET-Unit, gas boilers, and photovoltaics can result in 28% energy self-sufficiency, annual savings of over 2221 EUR, and a payback period of 7.4 years. The SET-Unit, combined with renewable energy sources such as photovoltaics, and the in-market available gas boilers or heat pumps, shows benefits in efficiency, annual energy cost reduction, and a relatively short payback period for the household. Using the low end of published values for capital expenses, economic feasibility can be achieved.