# Planning of High-Power Charging Stations for Electric Vehicles: A Review
###### Abstract
Furthermore, different charging technologies are being developed, ranging from static plug-in charging to dynamic technologies such as inductive and catenary charging. Depending on the use case, a particular technology can be more or less suitable for the charging process and achieve better results in terms of economic benefits. Another question that arises is: what type of vehicles should the CI serve in the long term? In the Paris Declaration on Electromobility, international parties recognized the need to electtify at least 20% of all road transport vehicles by 2030 [5], and many cities are setting ambitious targets of a modal shift from private passenger cars to sustainable modes: the Mayor of London's Transport Strategy aims for 80% of all journeys to be made by walking, cycling, or public transit by 2041 [6], whereas as of 2019 in Buenos Aires, only 14% of journeys are made with private motorized transport [4]. CI should therefore anticipate and accelerate a modal shift to reduce the overall ecological footprint of the traffic sector, rather than limiting the planning process for the exclusive use of passenger vehicles. Finally, the problem of allocating charging stations (CSs) can be reduced in its complexity by pre-selecting candidate sites where costs (such as land, grid connection) can be minimized and coverage of main traffic flows can be maximized. All in all, the need to provide final users with a CI that can supply energy to the EV fleet without compromising grid stability is crucial for the future of both transportation and electrical system planning. Increasing demand for motorized vehicles, coupled with the expanding economic capacity of society, will further enlarge the size of private vehicle fleets, which is expected to have tripled by 2050 compared to 2000 [7]. This growth has created social, environmental, and health issues, such as traffic congestion, air and noise pollution, greenhouse gas emissions, accidents, and physical inactivity among users. All of these factors are adverse to society in terms of costs, economic productivity, and environmental externalities [8]. A holistic spectrum of areas has been studied in order to mitigate losses derived from these factors and enhance the sustainability of the transport sector, including use of technology, infrastructure expansion, incentives for driving behavioural changes, limitations of car traffic, and aggressive land use policies [9]. The adoption of electric cars together with the CI planning can be described as a \"chicken-egg dilemma\", as pointed out by authors in [10]: replacing a fossil fuel-based mobility with an electric one is intrinsically connected to the CI that can enhance the transition in a mutual positive feedback-loop, as visualized in Figure 1. The negative drawback is that the lack of one element (either EV uptake or CI) can potentially hamper the loop, resulting in a situation of stall. Several authors investigated the level of development of the CI in order to better plan future actions and investments. In their literature review, authors in [11] found that approximately 10 optimally located fast chargers are sufficient for every 1000 EVs, but were unable to draw general conclusions based on the small amount of studies that were reviewed. It has since been found by [12] that 0.3-1.8 fast chargers per 1000 EVs are suitable, much like the VRI used for combustion engines. It was shown that 314 optimally located FCSs would be sufficient for serving the European highway network (0.7 per 1000 in Germany) [13] and 250 FCSs in the US highway network [14]. As stated by [12], this seems inconsistent, as more chargers are already currently available than this theoretical number. However, several empirical studies indicate similar results. A partial conclusion that could be drawn is that more efforts are needed in order to optimally locate and size charging stations, thereby increasing their utilization rate.