This video shows low photonic flux solar powered hydro electrolysis and solar-hydrogen fuel cell hybrid power...in action. The start of the video shows solar cells producing a sufficient amount of DC power to perform two functions: (1) drive the DC motor turning the wheels, and (2) stress the electro-chemical reaction for water electrolysis, splitting distilled water into it's constituent gases - hydrogen and oxygen.
The reason I call it "low photonic flux" is because this sunlight is later in the afternoon on a fall day, and not direct high-noon sunlight from the summertime.
Midway through the video, I open the circuit removing the power produced by the solar cells. The stored hydrogen and oxygen gases then recombine back to form water by the fuel cell, and this reaction produces electrical current to continue to drive the motor while the gas inventories deplete. The voltage drops and motor slows down only because of the specific components I have assembled.
This technology is scalable, as in one can use more photovoltaics for larger electrical loads and power production. Also the fuel cell shown is only a single cell, so more output voltage and current would be obtained by using a larger fuel cell stack.