# Electric Vehicle Penetration in Distribution Network: A Swedish Case Study
## 1 Introduction  
As a consequence of the United Nations' (UN) latest agreement in Paris in December 2015 on climate changes [1; 2] as well as due to the rapidly public increasing interest on Electric Vehicles (EVs), a number of European countries, including Sweden, and some states in the USA agreed to expand the market for EVs as an effort to reduce the amount of greenhouse gases [3]. As analyzed by [PERSON] et al. [4], if the number of EVs increases dramatically in Sweden, the electricity system could be possibly burdened. The problem might be even more intensive in a particular case where the owners of EVs would like to charge with higher currents than 10 A single-phase charging, which is typical today for a Swedish large customer. These barriers are better explained by [PERSON] et al. [5]. An extensive assessment of urban networks is provided by [PERSON] et al. [6]. However, EVs could provide ancillary power system services alleviating constraints [7] and congestions [8]. In Sweden, electricity consumption is mostly affected by cold winters, especially in areas where space heating is based on electrical units. In particular, in Karlstad, where the presented case study takes place, only about 5% of the households are not heated by electrical units. Sweden's power companies are regulated by the Energy Market Inspectorate, \"_Entergimarkandsinspektionen_\", to ensure that fees paid by the power companies' customers are maintained at a reasonable level [9]. According to Statistics in Sweden [10], the number of cars, buses, and trucks fully powered by electricity was around 290 at the end of 2008. If electric hybrid (EHs) vehicles were included, the corresponding number increases to approximately 13,800 vehicles, which could be connected tothe grid following, according to a study from [PERSON] et al. [11]. According to the same statistics, the amount of pure EVs was slightly more than 11,100 at the end of 2017 and, including EHs, the amount increases to more than 115,000. In 2017, almost 39,000 fully or partially EVs were registered in Sweden, which results in almost 34% of the total new registered vehicles. This indicates that the number of EVs and EHs will only increase over the next few years. Moreover, EHs contribute to the largest increment with almost 50% of the total over the last five years. Except from EVs, Plug-in EHs could also contribute to power system balancing [12]. It is of paramount importance for electrical grid owners, electrical grid operators, and all involved stakeholders to have an integrated knowledge with regard to future electrical power needs in order to establish a safe strategy for grid investments and new business models. As such, several future scenarios are explored in order to define suitable strategies toward a feasible solution with high penetration of renewable energy systems (RES), EVs, and energy storage devices (ESD) [13; 14]. In Reference [13], the prospects for realization of the 100% renewable energy system in North Macedonia by making use of the EnergyPLAN model is investigated. In the first scenario, a 50% RES has been created for the year 2030 as a first step toward the 100% future RES. In the second scenario, a 100% RES in the year 2050 has been designed. In Reference [14], a study is presented toward a 100% RES for Ireland based on the EnergyPLAN, since it accounts for all sectors of the energy that need to be taken into account for the integration of renewable sources such as the electricity, the heat, and the transport sectors. The investigation has been conducted by developing three different 100% RES with each focusing on a different resource. Specifically, biomass, hydrogen, and electricity resources have been used and compared with reference to the existing Irish energy system. There are several similar investigations based on future scenarios toward the development of a 100% RES. Each particular case study is unique because it includes its own special characteristics and requirements.