An energy management system includes an equipment data management unit which manages charging/discharging loss of a battery and heat radiation loss of an electric water heater, and causes a control unit to perform control to give priority based on the comparison to the energy storage facility more reducing loss and store energy. The energy management system includes a system operation calculation unit which predicts voltage distribution of the next day of a distribution system or demand-and-supply balance amount of the entire system by state monitoring data of a power system, calculates a demand amount increasing target value necessary for avoiding a photovoltaic power generation amount suppression on a consumer end by the voltage distribution of the next day of the distribution system or the demand-and-supply balance amount, and controls the energy storage facilities so as to satisfy the demand amount increasing target value on the consumer end.