TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The programmable logic controller is designed to control the operation of the installation by running a series of instructions stored in one of its components. The control unit is designed to control the operation of the installation in three possible modes such as hydrogen production mode in which the data provided by the user are the flow and pressure of installation operation regardless of the use of produced hydrogen and/or oxygen, hydrogen storage mode in which the installation feeds a unit for hydrogen storage and the data provided by the user are the flow and the filling pressure of the reservoir, and a hydrogen consumption mode in which the installation feeds a hydrogen consumption unit and the data is an initial flow regulated by the pressure. The programmable logic controller regulates the produced gas flow depending on the temperature measured by temperature sensor by changing the voltage generated by the direct current generator and applied to the terminals of electrolysis unit according to the gas flow provided by the user, and calculates the produced hydrogen flow using a coulometry equation of which input data is the current intensity in the electrolysis unit. The programmable logic controller performs in loop the instructions such as starting, measuring the water level in the second chamber, identifying whether the water level in the second chamber reaches the maximum level, opening the oxygen pressure regulator, taking the measurement of the pressure in the oxygen and hydrogen extraction circuit, identifying whether the pressure difference between the hydrogen extraction circuit and oxygen extraction circuit is greater than threshold, opening the first solenoid valve mounted on the pipe provided between the two level control chambers while maintaining that gap so that the second separation chamber is partially empty in the first separation chamber, closing the first solenoid valve and closing the oxygen pressure regulator when the water level in the second chamber reaches the minimum level or when the water level in the first chamber reaches maximum level, and back to start. The extraction of water is carried by a pipe towards a buffer storage reservoir that is connected to the second gas evacuation unit. The cooling/heating circuit comprises a first heat exchanger placed between the outlet of the first chamber and feeding the water electrolysis unit to exchange heat between the feeding water and the coolant, a unit for circulating coolant, a first three-way valve, a second heat exchanger contacting with a cold source, a third heat exchanger attached to the current generator as a hot source, a second three-way valve.