A power management device comprising: a communication module configured to receive information about solar power generated by a photovoltaic module, information about commercial power supplied to an internal power network, information about load power consumed in the internal power network, and information about an energy storage amount of at least one energy storage device; and being characterized by a processor configured to generate a charge command for charging of alternating current, AC, power from the internal power network to the at least one energy storage device or a discharge command for discharging of AC power from the at least one energy storage device to the internal power network based on at least one of the load power information, the commercial power information, the solar power information and the energy storage amount information, wherein the communication module transmits the generated charge command or discharge command to the at least one energy storage device, wherein, when a mobile terminal is in a whole mode of a power monitoring mode, the communication module receives a power monitoring request for the whole of the internal power network from the mobile terminal, and transmits monitored information for the whole of the internal power network to the mobile terminal, wherein the whole mode corresponds to a mode for monitoring the whole energy storage devices of the internal power network, wherein, when the mobile terminal is in an individual mode of a power monitoring mode and a first energy storage device item in an individual mode picture is selected, the communication module receives a power monitoring request for a first energy storage device from the mobile terminal, and transmits information about an energy storage amount of the first energy storage device, wherein the individual mode corresponds to a mode for monitoring one of the whole energy storage devices of the internal power network. a communication module configured to receive information about solar power generated by a photovoltaic module, information about commercial power supplied to an internal power network, information about load power consumed in the internal power network, and information about an energy storage amount of at least one energy storage device; and being characterized by a processor configured to generate a charge command for charging of alternating current, AC, power from the internal power network to the at least one energy storage device or a discharge command for discharging of AC power from the at least one energy storage device to the internal power network based on at least one of the load power information, the commercial power information, the solar power information and the energy storage amount information, wherein the communication module transmits the generated charge command or discharge command to the at least one energy storage device, wherein, when a mobile terminal is in a whole mode of a power monitoring mode, the communication module receives a power monitoring request for the whole of the internal power network from the mobile terminal, and transmits monitored information for the whole of the internal power network to the mobile terminal, wherein the whole mode corresponds to a mode for monitoring the whole energy storage devices of the internal power network, wherein, when the mobile terminal is in an individual mode of a power monitoring mode and a first energy storage device item in an individual mode picture is selected, the communication module receives a power monitoring request for a first energy storage device from the mobile terminal, and transmits information about an energy storage amount of the first energy storage device, wherein the individual mode corresponds to a mode for monitoring one of the whole energy storage devices of the internal power network.