A solar control device for being included in each of a plurality of panel control units, in a system in which the plurality of panel control units is connected to one battery for storage, each including a solar panel and a DC-DC converter , and for controlling the DC-DC converter such that electric power generated by the solar panel is controlled using a maximum power point tracking method, the solar control device comprising: an execution unit configured to cause the DC-DC converter to perform a scan process of scanning an output voltage of the solar panel and retrieving a maximum power point based on a predetermined instruction, and a determination unit configured to determine whether a predetermined first time has elapsed after the scan process has been previously completed, to additionally determine whether the electric power generated by the solar panel continues to be equal to or less than a predetermined first threshold value for a predetermined second time when it is determined that the first time has elapsed after the scan process has been previously completed, and to output the instruction to cause the DC-DC converter to perform the next scan process to the execution unit when it is determined that the electric power generated by the solar panel continues to be equal to or less than the first threshold value for the second time, characterized in that the determination unit is configured to additionally determine whether an absolute value of a change in a predetermined period of a terminal voltage of the battery is equal to or greater than a predetermined second threshold value when it is determined that the first time has elapsed after the scan process has been previously completed, and to decrease the first threshold value and to increase the second time when it is determined that the absolute value of a change in the predetermined period is equal to or greater than the second threshold value in comparison with a case in which the absolute value of a change in the predetermined period is less than the second threshold value. an execution unit configured to cause the DC-DC converter to perform a scan process of scanning an output voltage of the solar panel and retrieving a maximum power point based on a predetermined instruction, and a determination unit configured to determine whether a predetermined first time has elapsed after the scan process has been previously completed, to additionally determine whether the electric power generated by the solar panel continues to be equal to or less than a predetermined first threshold value for a predetermined second time when it is determined that the first time has elapsed after the scan process has been previously completed, and to output the instruction to cause the DC-DC converter to perform the next scan process to the execution unit when it is determined that the electric power generated by the solar panel continues to be equal to or less than the first threshold value for the second time, characterized in that the determination unit is configured to additionally determine whether an absolute value of a change in a predetermined period of a terminal voltage of the battery is equal to or greater than a predetermined second threshold value when it is determined that the first time has elapsed after the scan process has been previously completed, and to decrease the first threshold value and to increase the second time when it is determined that the absolute value of a change in the predetermined period is equal to or greater than the second threshold value in comparison with a case in which the absolute value of a change in the predetermined period is less than the second threshold value. <EOS>