A power management method in which a power management server that manages a facility connected to a power grid instructs a local control apparatus provided in the facility to control an equipment provided in the facility, the power management method comprising: a step A of transmitting a first message including a first information element indicating an information type of the equipment to which a report to the power management server is requested, from the power management server to the local control apparatus according to a first protocol; a step B of transmitting a second message from the local control apparatus to the equipment according to a second protocol different from the first protocol, wherein the second message corresponds to the report of the information type of the equipment for the equipment instructed by the first message and includes a second information element of the second protocol corresponding to the first information element of the first protocol; a step C of transmitting a second message response from the equipment to the local control apparatus according to the second protocol, in response to the second message, when the control content for the equipment instructed by the first message is a report of information on the equipment; and a step D of transmitting a first message response from the local control apparatus to the power management server according to the first protocol in response to the first message, wherein the step D includes: a step D1 of converting at least one information element complied with the second protocol and included in the second message response into an information element complied with the first protocol; and a step D2 of transmitting the first message response including the information element complied with the first protocol, and the step D1 of converting includes calculating, by the local control apparatus, the information element complied with the first protocol based on the at least one information element complied with the second protocol and included in the second message response, characterised in that the calculating includes calculating the information element complied with the first protocol and represented by AC power, on the basis of the information element complied with the second protocol and represented by DC power. a step A of transmitting a first message including a first information element indicating an information type of the equipment to which a report to the power management server is requested, from the power management server to the local control apparatus according to a first protocol; a step B of transmitting a second message from the local control apparatus to the equipment according to a second protocol different from the first protocol, wherein the second message corresponds to the report of the information type of the equipment for the equipment instructed by the first message and includes a second information element of the second protocol corresponding to the first information element of the first protocol; a step C of transmitting a second message response from the equipment to the local control apparatus according to the second protocol, in response to the second message, when the control content for the equipment instructed by the first message is a report of information on the equipment; and a step D of transmitting a first message response from the local control apparatus to the power management server according to the first protocol in response to the first message, wherein the step D includes: a step D1 of converting at least one information element complied with the second protocol and included in the second message response into an information element complied with the first protocol; and a step D2 of transmitting the first message response including the information element complied with the first protocol, and the step D1 of converting includes calculating, by the local control apparatus, the information element complied with the first protocol based on the at least one information element complied with the second protocol and included in the second message response, characterised in that the calculating includes calculating the information element complied with the first protocol and represented by AC power, on the basis of the information element complied with the second protocol and represented by DC power. a step D1 of converting at least one information element complied with the second protocol and included in the second message response into an information element complied with the first protocol; and a step D2 of transmitting the first message response including the information element complied with the first protocol, and the step D1 of converting includes calculating, by the local control apparatus, the information element complied with the first protocol based on the at least one information element complied with the second protocol and included in the second message response, characterised in that the calculating includes calculating the information element complied with the first protocol and represented by AC power, on the basis of the information element complied with the second protocol and represented by DC power.