Abstract The spread of wind turbines and photovoltaic modules for green electricity generation is stressing the need of installing large-scale electricity energy storage. Among the in-developing storage technologies, those which store electricity in the form of thermal energy are considered the most promising due to the absence of geological restrictions and long cycle life. In this context, the Authors of the present work, developed a large-scale electricity energy storage unit which uses air as working fluid and stores electrical energy as sensible heat in a man-made tank. As other thermal storage technologies, the proposed one does not suffer of geographical limitations, is characterized by long cycle life and can be assembled with decommissioned devices originally designed for gas turbine plants. In this work, the Authors analyse the plant energetic performance and the construction cost for different storage materials and plant management strategies. Results show that the thermo-physical properties of the storage medium and the charging tolerance affect the plant performance and costs. For these reasons, it is essential selecting the material based on the plant purpose: if the plant works with daily charge/discharge cycle, packed bed made up by limestone or masonry material is suggested while, for weekly charge/discharge cycles, aluminium oxide can be a better storage option.