Power management system and power management method

A power management method for controlling a power management system which is connected to a system power supply, and which, with respect to a storage battery in a first customer facility having a storage battery and a power generator as electrical equipment, controls discharge thereof to the first customer facility or charge thereof with surplus power generated in the first customer facility, the power management method comprising:

• a power consumption estimation step wherein, based on a first filter estimation function to make estimation by measured value of power consumption in a limited period of past measurement, a power consumption estimation unit estimates power consumption of next period of measurement in the first customer facility as an estimated power consumption,
• a power generation estimation step wherein, based on a second filter estimation function to make estimation by measured value of power generation in a limited period of past measurement, a power generation estimation unit estimates power generation of next period of measurement in the first customer facility as an estimated power generation,
• a surplus power estimation step wherein a surplus power estimation unit obtains an estimated surplus power which is a difference between the estimated power generation and the estimated power consumption, and
• a power management step wherein a power management unit controls each of the charge and discharge of the storage battery, based on the estimated surplus power obtained by the surplus power estimation unit.