Small capacity energy storage system

An energy storage system (ESS) for electricity generation uses electricity (or some other energy source, such as solar-thermal energy) to charge an energy storage system or device, which is discharged to supply (generate) electricity when needed at desired levels and quality. ESSs provide a variety of services to support electric power grids.

The new type of energy storage is an Electro-thermal Energy Storage System (ETES) that uses FPSE and thermal storage materials for sensible heat storage. The proposed ETES does not use any critical materials, and it is easy to disassemble and recycle.

As of the end of 2022, the total nameplate power capacity of operational utility-scale battery energy storage systems (BESSs) in the United States was 8,842 MW and the total energy capacity was 11,105 MWh. Most of the BESS power capacity that was operational in 2022 was installed after 2014, and about 4,807 MW was installed in 2022 alone.

The most common large-scale grid storages usually utilize mechanical principles, where electrical energy is converted into potential or kinetic energy, as shown in Fig. 1. Pumped Hydro Storages (PHSs) are the most cost-effective ESSs with a high energy density and a colossal storage volume .

Thermal Energy Storage (TES) can store thermal energy directly and at a large capacity. The most common TES systems are direct sensible, latent heat, and thermo-chemical storages. Their energy source is either solar thermal or industrial waste heat, where the end-use of these systems is for heating, drying and cooling purposes .

There exist several methods to store renewable heat or electricity. In Fig. 1, we have classified these energy storage systems into four categories of mechanical, electrical, chemical, and thermal storages.