ENERGY MANAGEMENT SYSTEM, ENERGY MANAGEMENT METHOD AND HOST ENERGY MANAGEMENT DEVICE

A power management system comprises a plurality of HEMSs 10 and a CEMS 40. The CEMS 40 transmits, to each HEMS 10, a notification request for requesting a notification of an amount of power that can be reduced from power currently consumed by a load connected to each HEMS 10, in response to a power curtailment signal. Each HEMS 10 transmits, to the CEMS 40, reducible power information including the amount of power that can be reduced from the power currently consumed, in response to the notification request. The CEMS 40 transmits, to each HEMS 10, power reduction information including an amount of power that should be reduced in each consumer 70, in response to the power curtailment signal and the reducible power information.