## 3 Calculation of emissions due to the operation of the electricity distribution network. One of the problems with the most studies on different EV interconnection modes is that \"these models often lack the ability to take the network infrastructure at lower voltage levels into account. The models assume that the infrastructure is strong enough to supply the EV demand.\" [24] (p. 5). However, several studies indicate that large-scale \begin{table}
\begin{tabular}{l c c c c c c} \hline \hline  & \multicolumn{2}{c}{**EV Life Cycle**} & \multicolumn{2}{c}{**Communications**} & \multicolumn{2}{c}{**EV**} \\  & & & **Infrastructure** & \multicolumn{2}{c}{**Total Partial**} \\ \cline{2-7}  & **Manufacturing** & **Charging** & **G2V** & **V2G** & **G2V** & **V2G** \\  & **gCO2e/km** & **gCO2e/km** & **gCO2e/km** & **gCO2e/km** & **gCO2e/km** & **gCO2e/km** \\ \hline Worst case & 66.7 & 76 & 41.35 & 66.69 & 184.048 & 209.24 \\ Best case & 46 & 60 & 19.66 & 31.68 & 125.66 & 137.68 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Summary of the calculation of emissions with the contribution of manufacturing, charging, and the installation and operation of telecommunications, control, automation, processing, and large-scale data storage infrastructures. EV integration will require the need for new infrastructure in the distribution network, as congestion leads to the need to expand or create new infrastructure [28]. An important consequence of the increase in EV usage for all interconnection modes is the increase in network losses. This problem will occur in the transport network when power comes from plants (whether renewable or not) that are located outside large centers. And it will always occur in the distribution network, since it will be this network that most EVs will be connected to. For NC and WCNC modes, prioritizing the connection of EVs at night can help mitigate the problem of congestion in the distribution network, since during this period, there is less power flow, and thus it is more likely that additional power flow of EVs can minimize the need for new infrastructure. However, it also implies additional losses in the network that would not exist if EVs were not used. Enabling charging from local renewable sources (solar, for example) and on an isolated island also reduces losses, since production and consumption is local [17]. But this option can only charge a small number of vehicles and may not always be available. Charging an EV allows (on average) for traveling 380 km with a consumption of 50 kWh, and charging the battery takes at least 30 min to obtain 80% of its value [13]. In regular charging mode, it will take 8 to 12 h to fully charge the battery. The infrastructure required for fast charging is very important for long journeys, and there must be charging stations at least every 20 km throughout the country [31], which implies a vast network and, as such, high cable losses due to high current and distance. The study carried out by [15] based on an urban network--considering 51% of EVs compared to the total number of vehicles, 90% of EVs charging at night and 35% during the day, and 10% of EVs operating in V2G mode during peak hours--indicates the following:  
* The increase (necessary due to EVs) in investment in reinforcing the installation or new installations in the distribution network, mainly in cables and protection equipment (does not include installations for charging EVs), will be around 14% for the scenario of 51% EVs (with simultaneity factor of 1). But this value could rise to around 19% if the scenario is 62% EVs. These values are due to the increase in consumption during peak hours. * The option for 95% of EVs to be charged during off-peak hours (95% in normal charging and 5% in fast charging) was the limit found for the network without the need for additional investment due to congestion during off-peak hours.