# PV Sizing for EV Workplace Charging Stations--An Empirical Study in France
## 1 Introduction  
On 4 November 2022, the French Senate enacted legislation mandating exterior parking stations for light-duty vehicles exceeding 1500 square meters to allocate at least 50% of their surface area to solar panels [1]. The French government has also established a series of financial incentives to accelerate the transition towards a sustainable transportation sector, encompassing both the purchase of electric vehicles and the installation of charging infrastructure. These legal obligations and incentives collectively pave the way for the widespread adoption of energy systems that integrate both PV and EV. Reviews of all the possible interactions between these two technologies are provided in [2; 3; 4; 5]. Amongst all these possible interactions, we consider that large PV-powered EV Charging Stations (PVCS) near workplaces are one of the most promising use-cases. First, from a technical point of view, in such a case, the EV charging demand (that lasts all the working day long)is \"nearly\" concurrent to the PV production. Second, if the number of EVs is large enough, this demand is also rather predictable. These two points a priori facilitate the optimization of the PV energy use. This use-case is also one of the simplest in terms of interactions between the stakeholders, rendering their cooperation possible, as proven experiments described in [6] and on a larger scale ten years later in [7]. Furthermore, when the PVCS are large enough (both in terms of PV capacity and the number of charging points), it takes advantage of the scale effect on costs. Finally, when the PV panels make car park canopies, the PVCS provides a better customer/worker experience (by shading the user's car and by offering EV charging service) and promotes the energy transition. In the context of large PVCS, several technical and financial stakeholders interact with each other [2]. An EV Charging Infrastructure (EVCI) with multiple charging points is managed by a Charging Point Operator (CPO). For the sake of simplicity, we consider that the EV driver interacts directly with the CPO, even if, in practice, another stakeholder called e-MSP (for e-Mobility Service Provider) sometimes acts as a third party between the CPO and the driver. Within the vicinity of the EVCI, ground-mounted PV plants and/or solar carports are installed and operated by a Photovoltaic Operator (PVO). In order to be as generic as possible, we assume that PVO and CPO are distinct legal entities. We consider that the PV plant and the charging stations are both connected to the distribution network, managed by the Distribution System Operator (DSO), but are associated with two different connection points (i.e., they have two different power meters). These power connections serve a dual function; they provide power to the EV stations during periods of insufficient PV generation and enable the surplus PV energy to be injected into the grid when there is an excess of production. Sizing PVCS at the earliest design step is crucial, especially for the CPO, because such sizing will be the basis for the next design phases. However, this step is a particularly difficult task. First, by essence, the technical details of the final PVCS, such that the IT and power architecture and the EV charging control algorithms (if any), are unknown. Thus, during the sizing phase, the designer has to choose models that not only have to be \"rough\" (i.e., that do not include technical details) but also have to correspond to feasible and practical technical solutions. Second, data about the EV demand (i.e., arrival/departure times and energy needed to fill the EV batteries) that spans a large time horizon (at least half or one year) is key data to size the PVCS. In general, such data is not available or is of poor quality at this stage. Third, many business interactions between the different stakeholders can be imagined, rendering the formalization of a generic sizing method rather difficult. The objective of this paper is to provide a method that encompasses these difficulties.