Energy Storage Options for Electric Vehicle Recharging Stations

The projected increased usage of electric vehicles (EVs) in the coming decades will create a need for development of EV battery-recharging stations. To avoid adding to peak electric loads, daytime recharging can be met using stored energy. Possible energy storage options include superconducting magnetic energy storage (SMES), batteries, flywheels, and compressed air storage. This paper compares these options along with generation technologies (i.e., flywheels and combustion turbines) for stations ranging from 0.1 to 10 MWh of storage per facility on the basis of cost, operating features, maintenance, and maturity. Also discussed are the issues of interfacing energy storage sources with various charging approaches, including direct connection to the vehicle and inductive coupling. We also address the need for energy storage development to meet the projected electric vehicle infrastructure needs of the next century.