*2.2. Vehicle to Home (V2H)*

This technology refers to the systems in which the energy stored in batteries of the electric vehicles can be used as an energy source for houses [35]. For example, during the night, when power consumption is low on the grid, the battery can be charged and the stored energy can be sold to the grid when the energy consumption is high on the grid [36]. The V2H block diagram is shown in Figure 5. The electric vehicle is plugged into a charging station from where it gets energized. An energy management system and a home load manager are connected in parallel to the vehicle. The controllable switch before the transformer with the main grid controls whether power will be exchanged with the main grid or not. When the switch is open, the vehicle transfers energy to the home loads. The energy management system serves to supervise the energy transfer to ensure that everything is working normally. The size for a battery energy storage system in residences can vary from 3 to 30 kWh depending upon the manufacturer [37]. Therefore, V2H technology can play a significant role in exploiting EV energies to power up residential loads.

**Figure 5.** Block diagram of the V2H structure [36].

The infrastructure of V2H technology is similar to the V2G structure. The main activity in this case is to transfer energy from vehicles to houses, buildings, or other electrical vehicles in line with the existing energy capacity [38]. However, there are critical conditions for energy transferring. The most important of these conditions is the amount of energy.

As depicted in Table 1, if the energy is to be transferred to a detached house from an electric vehicle, the amount of power in the electric vehicle must be between 5 and 10 kW. In case of transferring from an electrical vehicle to a building, it must be between 10 and 15 kW. Or, if the energy is transferring from an electrical vehicle to another electrical vehicles, this value must be between 15 and 30 kW [39]. These standards are very important for energy efficiency, continuity, and reliability [40].


**Table 1.** Vehicle-to-X energy transfer range [39].
