The purpose of the present invention is to allow for a suitable power management by evaluating the reliability of an information source that provides climate conditions and so forth. A load power management system is provided with: a communication unit that acquires as public information external information including at least either the supply information for commercial power or climate information; an information storage unit that stores at least public information, measured climate information and system operation history information; a central control unit that acquires the public information and measured climate information, assesses the reliability of acquired public information on the basis of the measured climate information, and outputs a power management command that issues an instruction to supply power to a load on the basis of highly reliable public information; a power source switching circuit that manages the states of a plurality of power sources while performing the output control thereof; a
