What are the different types of energy storage technologies?

Among large-scale storage technologies, electrochemical (flow batteries, FBs), mechanical storage (pumped hydro storage, PHS), and compressed air energy storage (CAES) are considered the most mature and commercially available solutions.

What is integrated energy storage system (I-ESS)?

The arrangement is named the “Integrated Energy Storage System” (I-ESS) and consists of a thermo-mechanical unit for storing electricity in the form of sensible heat that allows the use of components of existing unused or in-decommissioning fossil-based power plants.

How much electrical energy is produced during a complete discharge process?

The electrical energy produced during a complete discharge process results in 31 MW h e l. Note that for the hypothesis of the investigation performed, the charge phase is not modelled. Therefore, the Round-Trip Efficiency (RTE) cannot be defined on the basis of the selected starting state of charge.

What determines the discharge time at nameplate power?

The storage temperature also determines the discharge time at nameplate power. Varying the TES temperatures from 1100 K to 1300 K, we observe an increase by 61% of the discharge time.

What is pumped thermal energy storage (PTEs)?

Despite the various solutions proposed, the most studied CB plant arrangement is the one named Pumped Thermal Energy Storage (PTES). PTES is characterised by a high energy density, a low self-discharge rate, no geographical limitations, and a small installation footprint.

How do you calculate the efficiency of the discharge phase?

However, considering the TES as isothermal at a temperature of 1200 K, the efficiency of the discharge phase can be computed as in Eq. (12), and resulted equal to 27% (12) η d i s c h a r g e = E e l, d i s c h a r g e E t h, d i s c h a r g e This has to be considered as an average value.