Energy storage sizing for plug-in electric vehicle charging stations

To support, plug-in electric vehicle (PEV) growth, there is a need to design and operate charging stations without increasing peak system demand. In this chapter, first, an overview of on-going demonstration and testing studies are presented to show the complexity of the actual charging infrastructures and uncertainties related to customer demand. Then, an analytical model for a large-scale charging station with an on-site energy storage unit is introduced. The charging system is modelled by a Markov-modulated Poisson Processes with a twodimensional Markov chain. A Matrix geometric based algorithm is used to solve steady state probability distribution to compute optimal energy storage size. Case studies are presented to show (i) the relationships between energy storage size, grid power and PEV demand and (ii) how on-site storage can reduce peak electricity consumption and the station’s monthly electricity bill.