NOVELTY - The hydrogen-production system has hydrogen-production apparatus (5), solar cell (1), storage battery (3), and control apparatus (4). The solar cell generates electric power using sunlight and supplies electric power to hydrogen-production apparatus. The battery supplies electric power to hydrogen-production apparatus, and control apparatus controls power-supply electric power of solar cell and charge of storage battery.    USE - For manufacturing hydrogen for use as fuel or heat source of fuel cells.    ADVANTAGE - The hydrogen-production system supplies electric power from a storage battery according to the demand of the hydrogen-production apparatus. The output of solar-power-generation installation and the scale of hydrogen-production apparatus are optimized. Hydrogen is manufactured economically and continuously.    DETAILED DESCRIPTION - The hydrogen-production system has a hydrogen-production apparatus (5), a solar cell (1), a storage battery (3), and a control apparatus (4). The hydrogen-production apparatus generates hydrogen by electrolysis, and the solar cell generates electric power using sunlight and supplies electric power to the hydrogen-production apparatus. The storage battery supplies electric power to the hydrogen-production apparatus, and the control apparatus carries out power-supply electric power control of the solar cell and charge control of the storage battery. The control apparatus has:    (1) solar-cell voltmeter measure circuit (6) to measure the output voltage of the solar cell;    (2) charge circuit (7) for charging the storage battery by the output of solar cell;    (3) storage-battery voltmeter measure circuit (8) to measure voltage of the storage battery and to prevent overcharge and overdischarge;    (4) discharge circuit (10) to discharge the electric power of the storage battery;    (5) output circuit (11) for applying the output electric power of the solar cell and the output electric power of the storage battery to the hydrogen-production apparatus;    (6) timer (9) for setting the electric power supply time to the hydrogen-production apparatus; and    (7) arithmetic unit for comparing the output electric power of the solar cell and the required electric power of the hydrogen-production apparatus.    DESCRIPTION OF DRAWING(S) - The figure shows the block diagram of the control apparatus. (Drawing includes non-English language text).    Solar cell (1)    Storage battery (3)    Control apparatus (4)    Hydrogen-production apparatus (5)    Solar-cell voltmeter measure circuit (6)    Charge circuit (7)    Storage-battery voltmeter measure circuit (8)    Timer (9)    discharge circuit (10)    output circuit (11)