AbstractThe energy sustainability, in the era of sources diversification [1], can be guaranteed by an energy resources utilization most correct, foreseeing no predominance of one source over the others in any area of the world but a proper energy mix, based on locally available resources and needs [2]-[4]. In this scenario, manageable with a smart grid system [5], [6], a virtuous use of RES must be visible, recognizable and quantifiable, in one word traceable [7]. The innovation of the traceability concept consists in the possibility of having information concerning the exact origin of the electricity used for a specific end use, in this case EV charging [8]. The traceability, in a context of increasingly sustainability [9], [10] and smartness city, is an important develop tool because only in this way it is possible to quantify the real emissions produced by EVs and to ensure the real foresight of grid load. This paper wants investigate the real ways to introduce this kind of real energy accounting, through the traceability.