A power generation amount output device configured to output a power generation amount of a photovoltaic panel having been installed in a vehicle to a display unit, includes a power generation amount obtainment unit configured to obtain the power generation amount of the photovoltaic panel; a fluctuation reduction unit configured to reduce a fluctuation of the power generation amount to be output by the display unit, depending on a vehicle state of the vehicle; and a power generation amount output unit configured to output the power generation amount having the fluctuation reduced by the fluctuation reduction unit to the display unit.