TECHNOLOGY FOCUS - MECHANICAL ENGINEERING - Preferred Component: The electrolyzer module comprises temperature regulation device(s) coupled to the electrolyzer cell(s) for varying the operating temperature of electrolyzer cell(s) so that the current draw of the electrolyzer cell is controlled, drying unit coupled to the cathode of the electrolyzer cell(s), additional pressure regulating device coupled between drying unit and hydrogen storage module so that pressure fluctuations of the drying unit are also isolated from the hydrogen storage module, and pump to provide water to the electrolyzer cell at a flow rate and at sufficiently low pressure so that a determined differential pressure limit is not exceeded. The temperature regulation device(s) comprises heat exchanger for varying the temperature of water entering the electrolyzer cell(s). The electrolyzer cell(s) operates at constant operating voltage while its operating temperature is varied. The operating temperature is varied using temperature regulation device(s) so that variations in the current draw are a function of variations in the operating temperature or maintained constant. The pressure-regulating device is a mechanical regulating valve, dome loading pressure-regulating valve, or dome loading back pressure-regulating valve. The pressure-regulating device comprises inlet for receiving gas from the anode or cathode of the electrolyzer cell(s). It opens to allow gas flow to flow from inlet to outlet of the pressure-regulating device when the pressure at the inlet exceeds the pressure of the dome load signal. The water is supplied to the electrolyzer cell(s) in the hydrogen generation mode through pump at a rate associated with a desired rate of hydrogen production through electrolyzer module. The pump is a centrifugal pump. The fuel cell power module comprises oxidant-supplying device(s) to supply an oxygen-containing gas to the fuel cell(s) so that the rate where oxygen-containing gas is supplied by oxidant supplying device(s) is a function of current draw(s) on t he fuel cell(s) during operation of the fuel cell in electricity generation mode. The oxidant supplying device(s) comprises air blower(s). The rate where oxygen-containing gas is supplied through oxidant supplying device(s) is also a function of stoichiometric data predetermined for the system. The fuel cell power module further includes voltage monitoring device coupled to the fuel cell(s), pressure regulating device coupled to anode or cathode of the fuel cell(s), fuel cell(s) having anode and cathode, first connection(s) for coupling the fuel cell to hydrogen storage module containing hydrogen, and second connection(s) for coupling the fuel cell(s) to a load to be drive using fuel cell(s). The rate where oxidant-containing gas is supplied by oxidant-supplying device is also dependent on measurements obtained using voltage monitoring device. The hydrogen storage module comprises storage unit of cylinder(s) having metal hydrides for storing hydrogen generated using electrolyzer cell(s), and water circulation system coupled to the storage unit and fuel cell(s). The water is circulated in water circulation system in hydrogen generation or electricity generation modes. The waste generated using fuel cell(s) is transferred to the water in the electricity generation mode to enhance desorption of hydrogen in the hydrogen storage module. The storage unit is sized so that the waste heat generated using fuel cell(s) is sufficient to desorb hydrogen at a specified rate of hydrogen flow. The heat generated using hydrogen storage module in the hydrogen generation mode is transferred to the water to preheat the fuel cell(s). The water circulation system comprises a water jacket where water may circulate, and internal cooling loop in the storage unit where water may circulate to facilitate transfer of heat between storage unit and water. The water jacket surrounds a part of the storage unit to facilitate transfer of heat between storage unit and water.