A photovoltaic module comprising: a photovoltaic solar cell; a converter to convert a level of a direct current power from the photovoltaic solar cell; an inverter to convert the direct current power from the converter into an alternating current power; a controller to control the converter and the inverter ; and a communication unit to perform electric power line communication with a gateway and at least one nearby photovoltaic module, wherein the communication unit is configured to periodically transmit communication state information to the gateway and the at least one nearby photovoltaic module using the electric power line communication, wherein the communication unit is configured to receive a message from the gateway along a path determined based on information on a routing tree for a plurality of photovoltaic modules, which is generated in the gateway based on the communication state information, and transmit the received massage to a first photovoltaic module of the at least one nearby photovoltaic module, wherein the routing tree indicates that a plurality of photovoltaic modules (50a~ 50n) are categorized into branch photovoltaic module to perform direct data communication with the gateway and leaf photovoltaic module to perform data communication with the branch photovoltaic module instead of the direct data communication with the gateway, wherein in a case where it is detected that the electric power line communication between the gateway and the photovoltaic module is temporarily stopped, the communication unit is configured to not perform direct communication between the gateway and the photovoltaic module , and perform message transmission between a second photovoltaic module and the photovoltaic module for performing message transmission between the second photovoltaic module and the gateway . a photovoltaic solar cell; a converter to convert a level of a direct current power from the photovoltaic solar cell; an inverter to convert the direct current power from the converter into an alternating current power; a controller to control the converter and the inverter ; and a communication unit to perform electric power line communication with a gateway and at least one nearby photovoltaic module, wherein the communication unit is configured to periodically transmit communication state information to the gateway and the at least one nearby photovoltaic module using the electric power line communication, wherein the communication unit is configured to receive a message from the gateway along a path determined based on information on a routing tree for a plurality of photovoltaic modules, which is generated in the gateway based on the communication state information, and transmit the received massage to a first photovoltaic module of the at least one nearby photovoltaic module, wherein the routing tree indicates that a plurality of photovoltaic modules (50a~ 50n) are categorized into branch photovoltaic module to perform direct data communication with the gateway and leaf photovoltaic module to perform data communication with the branch photovoltaic module instead of the direct data communication with the gateway, wherein in a case where it is detected that the electric power line communication between the gateway and the photovoltaic module is temporarily stopped, the communication unit is configured to not perform direct communication between the gateway and the photovoltaic module , and perform message transmission between a second photovoltaic module and the photovoltaic module for performing message transmission between the second photovoltaic module and the gateway . <EOS>