# PV Sizing for EV Workplace Charging Stations--An Empirical Study in France
## 2 State of the Art  
### Research Positioning  
There are four stages in the procedure of project development of an energy system [8]. * The first one is the \"idea development.\" It consists of \"brainstorming and idea generation activities to give the project a more rounded shape\";
* The second one is the \"concept development\" which describes the scope of the project (case descriptions, investment context, system and stakeholder overviews, etc.). It also specifies the resources required and estimates key financial (such as revenue stream, CAPEX, OPEX, etc.) and technical figures. Amongst them, the size of the main components of the system is determined. For example, the sizing of PVCS consists in determining one or all of the following quantities: the maximum power that the PV plant may deliver (also called \"peak power\"), the number of charging points (and possibly the maximum power that each of these charging points may deliver), the number of EVs that may be charged on the PVCS, or the capacity and the maximum power of the storage system. For such sizing studies, EV demand (number of daily EVs and their arrival and departure time), users' behavior, and vehicles' characteristics are the most imperative type of input data. Other types of input data are also required, such as incentives, taxes, grid codes, PV potential, etc. The concept development phase also determines the project risks, its social and environmental impacts and its profitability;
* The third stage is called \"business development\" and outlines all the actions needed to make \"real\" the system sketched during the previous phase. During this phase, the system is first designed in detail and an operation plan to build it is provided;
* The last stage is dedicated to the project execution. This phase entails the construction and installation of the final system, plus any other civil work needed for the project operations. The concept development phase usually consists of a prefeasibility study (PFS) and a feasibility study (FS). As explained in [8], \"the PFS scans a series of options and determines the best one in the set. The FS analyzes in depth the best solution from the prefeasibility phase. The PFS reduces the number of options that are chosen to proceed with a more detailed feasibility study and eventually with business development, ultimately saving time and money\". The objective of this paper is to provide a method to size PVCS during the early steps (i.e., during the PFS) of the concept development phase. As explained in [9], such sizing is particularly crucial, especially for the CPO, because it is considered a strong basis for the business development phase. Such sizing is a particularly difficult task because many of the details of the final system are not known. For example, much data necessary for sizing the PVCS is not available or is of poor quality at this stage. To circumvent this difficulty, EV demand could, for example, be synthesized from statistical distributions derived from experimental data [10]. However, due to daily and seasonal variations, this data also have to span a large time horizon (at least half or one year). Moreover, the details of the power infrastructure, of the IT architecture and of the control system that will be implemented on the final system are also generally not known. In the following, the term \"control system\" covers the algorithms (classified into scheduling, clustering and forecast in [11]) and all the interactions with the IT and the power systems that aim at optimizing the PVCS functioning for a given objective (expressed in terms of financial, efficiency and environmental [4]). Thus, the person who conducts the concept development phase has to use models of the control system that describe the behavior of the final one in a way as relevant as possible, but such models also have to be simple enough to explore many design possibilities [12].