*2.1. Impact of Digitalization on Energy Demand in Electrified Vehicles*

Digitalization is having a major impact on the transport and automotive industry, especially on EVs and HEVs. How significant this revert will be in the future will vary for each sector, and particular, application. The transport sector is becoming smarter and more connected, improving on safety and efficiency. In electrified vehicles, connectivity is empowering new mobility dividing services. Digitalization depicts the increasing application of information and communications technologies (ICT) across the economy, including energy systems. Advances in big data analysis, analytics, and connectivity enable the trend toward greater digitalization, as follows:


Mixed with the advances in vehicle automation and electrification, digitalization will result in significant but uncertain energy and emissions impacts.

### *2.2. Current Impact of EVs on Energy Demand*

In 2017, the estimated global electricity demand from all EVs was 54 terawatt-hours (TWh) (see Figure 2), an amount corresponding to little more than the electricity demand of Greece [5]. China has worldwide leadership of this demand (91%), and its energy consumption is mainly due to two-wheelers and buses. These two modes combined account for 87% of EV electricity demand worldwide. Yet, the electricity demand for LDVs has increased the fastest since 2015 (143%), followed by buses (110%) and two-wheelers (13%).

Figure 2 shows that the approximated electricity demand from EVs in 2017 increased by 21% compared with 2016. With reference to last year (2017), the electricity demand of the EVs corresponds to 0.2% of the total global electricity consumption [5,6,19]. In countries like China and Norway, which have the largest fleet and market share of EVs, the electricity demand of EVs is still below 1% of the total demand—0.45% in China and 0.78% in Norway. As yet, the expanding numbers of EVs have had a limited impact on the electricity demand, thus providing support of confidence for the transition to greater electric mobility. As electric vehicles are started growing, they will increase electricity demand and with that will affect transmission and distribution grids.

**Figure 2.** EV electricity consumption by country in 2017 from EVs.

#### *2.3. Possible Issues and Solutions to Integrate EV Electricity Demand in Power Networks*

Strong peaks characterize the demand for energy in the transportation sector in the morning and in the evening on weekdays, with limited variations across modes. Power demand also displays a morning and an evening peak in most regions, while the demand is lower during the night and in the afternoon. The low period of power demand during daytime is less visible for the summer days in warm climates, where there is a high electricity demand from cooling appliances, or in winter days in cold climates, because of the higher power demand for heating purposes.

Figure 3 shows a scenario with day changes in traffic flow in three different cities from three continents, Hong Kong (China), Long Beach (CA, USA), and Manchester (UK). Figure 3 also shows the electricity load curve of each region. The power demand and road mobility demand are both characterised by two peaks during the morning and evening hours, and a period of low demand during night time.

**Figure 3.** Road traffic and power demand profile during an average weekday for three cities from three different continents.

In all three cities, analyzed in Figure 3, as it is expected, there is a peak in traffic activity in the morning after a period of low electricity demand during the night. These specific features of electricity demand and transport activity point out that the overnight charging of EVs is well timed, before they are used in the morning. Moreover, the overnight charging of EVs has the added benefit of minimizing both the need for incremental electricity generation capacity and investment in distribution infrastructure upgrades.

The peak in electricity demand often follows the traffic peak in the evenings. Plugging EVs into the grid after the evening traffic peak may exacerbate the peak power draw. This couples with a higher risk of overloading of the power distribution network, requiring grid upgrades such as the replacement of distribution transformers and cables [23]. If not properly managed, the increased power draw at peak times could also require additional generation capacity. To avoid the economic and environmental effects of an increased peak load demand in the evenings, transferring the load to the night is advised.

Demand-side management (DSM), also called demand-side response, is an important tool that can significantly reduce the need for grid upgrades and additional generation capacity, because of the electrification of road transport, as well as facilitating the integration of renewable energy sources (RES) [5,6].

Regulators, utilities, transmission system operators, distribution system operators, and retailers are already taking DSM measures and designing policy mechanisms to ensure that the EV uptake will not overload the power grid. For EVs, DSM largely consists of the optimization of the charging time of the vehicles, shifting the loads to ensure a good match between the power supply and demand, with the aim of moving the bulk of the EV charging related power demand from the evening peak to the night. In addition to relieving the load on the distribution grid and reducing the investment needs for grid reinforcements, achieving this has the capacity to deliver a number of potential benefits, such as:


Realizing these benefits with DSM is facilitated by the implementation of a dynamic tariff policy such as time-of-use (TOU) pricing and/or real-time pricing (RTP) [24]. TOU pricing incentivizes consumers to charge EVs in a way that maximizes the power draw when electricity prices are low and minimizes it when they are high.

Dynamic pricing aims to discourage EV owners from charging their vehicle at peak times. However, it can also be used to shift the demand towards times when electricity production from RES is abundant, or to get all these benefits concurrently.

The charging process should be assisted by smart charging applications. Manufacturers such as BMW already have developed products to optimize the home charging process in an automatic way to benefit from low electricity prices [25]. DSM products may also be used to optimize the usage patterns of other residential appliances (e.g., heating and cooling) that contribute to electricity peak loads. Integrated systems may enable consumers to prioritize appliances, for instance, by temporarily reducing the electric heating to offset any additional load from charging an EV during the peak load.

DSM can also provide valuable ancillary services to the power grid, including frequency regulation, voltage support, and power factor correction, as well as the possibility to balance loads

across the distribution network. The effectiveness of DSM measures could be further enhanced by a bidirectional "vehicle-to-grid" (V2G) capability. V2G is a bi-directional connection between the EV and the grid through which power can flow from the grid to the vehicle and vice-versa [25,26].
