Electric Vehicles (EVs) have the potential to provide numerous ancillary services to the grid owing to the fact that they can act as either loads or sources when connected to the grid. However, customers are still disinclined to embrace this technology because of long battery charging time, limited range, and high battery replacement costs. Widespread rollout of fast Electric Vehicle Charging Stations (EVCS), however, could solve these shortcomings as they make services readily available for them and work as the stimulus for the future growth. Seemingly, reliability of those services by EVCS depends upon the optimum design of it, since over-dimensioning may render it as uneconomical or conversely, technically unreliable for the case of under-dimensioning. In this paper, an algorithm is developed for optimum sizing of Photovoltaic (PV) panel, Battery Energy Storage System (BESS) and Grid Transformer for an EVCS circumscribed by the grid constraints.