NOVELTY - The water production system comprises an air carrier pipe (2) extending from a lower level and an upper level, a unit (3) for heating the collected air at the lower level, a heat exchanger (4) connected to the air carrier pipe and located closer to the upper level than the lower level, and a unit for water collection formed by condensation of the heat exchanger. The carrier pipe is adapted to carry collected air at lower level towards the upper level. The heat exchanger is located at the top level to exchange heat between the carried air through the air carrier pipe.    USE - The system is useful for the production of water in rural desert to produce electricity.    ADVANTAGE - The system allows industrial and economical production of water in rural desert with less consumption of energy by effectively promoting the condensation of water vapor while maintaining a desired flow of air, and prevents a major portion of condensed water from leaking into the air transport conduit.    DETAILED DESCRIPTION - The water production system comprises an air carrier pipe (2) extending from a lower level and an upper level, a unit (3) for heating the collected air at the lower level, a heat exchanger (4) connected to the air carrier pipe and located closer to the upper level than the lower level, and a unit for water collection formed by condensation of the heat exchanger. The carrier pipe is adapted to carry collected air at lower level towards the upper level. The heat exchanger is located at the top level to exchange heat between the carried air through the air carrier pipe and the air collected at the upper level, and for cooling a part of the air heated by the heating unit. The air carrier pipe has a length of greater than or equal to 1000 m. The heat exchanger comprises an air inlet (5e) connected to the air carrier pipe and adapted to admit the air carried by the pipe in the exchanger, and an air outlet (5s) adapted to evacuate the air to the heat exchanger. The outlet is connected to cool the air pipe by the heat exchanger. A unit is arranged for generating electricity by collecting a part of the energy produced by airflow in the system, and is connected to a cool air pipe (8) for collecting energy generated by cool air circulation unit. The electricity generation unit comprises a series of ballasts hydraulically connected between each other in series. Each ballast is arranged at heights (H1, H2), which are monotonically increasing from 0 m to 14 m, and satisfies a relation corresponding to the conditions of permitting the passage of ballast liquid laid at the lower height in ballast and at the upper height (H2), and prohibiting the passage of ballast fluid from the upper height (H1) of the ballast. Each ballast is equipped with venting units, which are adapted to adopt selectively a configuration for placing the ballast in low pressure in which an upper part of the ballast is connected to the cool air pipe, and a configuration for pressurizing the ballast. The connection between the upper part of the ballast and the cool air pipe is prohibited, and the upper part of the ballast is then placed in the ambient air outside the ballast. A pipe is arranged for dropping the liquid in the ballast arranged at the upper height and the lower height. An electric generator is coupled to a propeller arranged to collect energy in a liquid stream flowing in the liquid dropping pipe. The heating unit comprises an enclosure having a partially transparent wall and peripheral to the air carrier pipe. The enclosure is filled with a gaseous fluid. Mirrors are placed at a distance from the air carrier pipe and swiveling with respect to the air carrier pipe to direct solar radiation along the air carrier pipe. An electric heater is used for heating the gaseous fluid within the enclosure. A part of the electricity generation unit is connected to the electric heater for feeding electricity. Balls are arranged for providing heat accumulation inside the enclosure and outside the air carrier pipe. Each of the balls comprises a spherical wall comprising a first hemisphere made of transparent material and a second hemisphere of which an external surface is black and an inner surface is made of light reflecting material.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of a system for producing water and electricity.    Air carrier pipe (2)    Heating unit (3)    Heat exchanger (4)    Air inlet (5e)    Air outlet (5s)    Cool air pipe. (8)