Volume 62

Decentralized Energy Storage with Metal Hydride – Phase Change Material Hybrid Systems Marco Maggini, Simone Pennesi, Piergiovanni Domenighini, Andrea Luigi Facci, Stefano Ubertini

Abstract

Seasonal energy storage may represent an important step for the energy transition, reducing both energy consumption and greenhouse gas emissions. This paper presents an analysis of an integrated energy system designed to power a building by combining energy production and storage. The system studied in this paper consists of photovoltaic panels, an electrolyzer to convert excess energy into hydrogen, a metal hydride tank, and a fuel cell for reconversion to electricity. The aim of this paper is to evaluate the energetic and economic performance of this system under various climatic scenarios and for different storage capacities. The results demonstrate that the system can overcome the seasonal mismatch between production and consumption of a 1-apartment building, with a self-sufficiency ratio > 98% and a PV system < 6kW. Economic-wise, the system needs an initial investment of ~120 k€ and a payback period 11÷22 years depending on the storage capacity, thus confirming substantial challenges for the scalability of metal hydrides in residential buildings. Their cost accounts for nearly 38% of the total investment costs.

Keywords renewable energy resources, hydrogen technologies, mitigation technologies, metal hydrides, energy systems, climate change