The article describes the experimental studies of hydrogen (oxygen) generation processes by the electrolysis method that were fulfilled with the use of the energy plant model involving a solar energy photovoltaic converter (working surface area is of S = 1.5 m2) and a membrane-less high-pressure electrolyzer (capacity is of 0.002 m3 of hydrogen per hour with an operating pressure of 0.3 MPa). Under experimental studies we have adjusted the modes of joint operating the photoelectric converter and the membrane-less high pressure electrolyzer depending on the changes of solar insolation. We have determined the ways to increase the electrolyzer efficiency. It was found that the level of current density, which determines the electrolyzer efficiency by hydrogen, depends on the solar insolation level. The obtained experimental data, as to adapting an electrolyzer to be feed from a photoelectric converter, give the possibility to develop the algorithms of automatic control of the electrolyzer when it operates in composition of an autonomous energy plant.