Electric vehicles（EVs）may play a dual role when plugged in a microgrid.EVs can be regarded as loads during charging while also used as storage units to supply energy to the remaining loads in the microgrid if the batteries have sufficient spare energy.In consideration of the EVscharacteristic of bidirectional energy flow in a microgrid，the energy dispatching model and strategies for the microgrid consisting of wind generators，photovoltaic systems and battery storages，EVs and other local loads are developed to analyze the impact of incorporating EVs on the economical operation of the microgrid.Simulation results show that the incorporation of EVs in microgrids can not only reduce the capital cost of storages and operation cost of the microgrid，but also save the cost of EVsowners.