An energy management system includes an energy management controller and a power conditioning system that charges and discharges a storage battery installed in an electric vehicle. The energy management controller includes: a charge/discharge controller that is configured to, in accordance with an operation mode having an operation right among a plurality of operation modes, control charging and discharging of the storage battery through the power conditioning system; and an operation right granter that is configured to determine an operation mode to which the operation right is to be granted next based on a predetermined transition condition, and to grant the operation right to the operation mode determined thereby.