1.2.2. Smart Grid

Existing equipment may be energized with EES and be included into the smart grid. By employing a home energy management system to track their actual usage in real time, residential consumers will take an active role in changing their energy consumption patterns [15]. EVs are projected to be a new source of electricity as well as a potential storage medium in a smart grid that uses a portable, distributed energy resource as a load-shifting function, allowing utilities to continue delivering power even as electricity costs rise.

#### **2. Types of Electrical Energy Storage System (EES)**

EES systems classified on the basis of the kind of energy consumed are: (i) mechanical, (ii) electrochemical, (iii) chemical, (iv) electrical, (v) thermal and (vi) superconducting magnetic categories [8,12,16]. The classification of EES based on type of energy consumed is shown in Figure 2.

**Figure 2.** Classification of EES based on type of energy consumed.
