A multipurpose plant for generating electricity and making available products obtained from salt water, comprising: - a first, upper tank for containing salt water, - a second, lower tank for temporary storage of the salt water, - a first pipe and a second pipe provided with respective closing means (21, 22) and designed to put in fluid connection the first tank and the second tank; - at least one hydroelectric turbine, acting along the first pipe and activated by the flow of water along the first pipe, for converting kinetic energy into electricity; - at least one pumping unit, acting along the second pipe and which can be activated for transferring the salt water from the second tank to the first tank; - a photovoltaic apparatus designed to convert solar radiant energy into electricity; - a desalination apparatus, designed to be put in fluid connection with the second tank for receiving at least one portion of the salt water from the second tank and for separating the salt water into salt and water, thus making the salt and the water available, the first tank, the second tank, the desalination apparatus and the photovoltaic apparatus being housed in the same tower structure; - an apparatus for performing electrolysis, designed to be put in fluid connection with the desalination apparatus for receiving the water and performing the electrolysis of the water, separating the water into hydrogen and oxygen; - a control unit, designed for allowing a plant management operator to control activation/deactivation of the desalination apparatus, of the pumping unit, of the electrolysis apparatus and to control opening/closing of the above-mentioned closing means (21, 22). - a first, upper tank for containing salt water, - a second, lower tank for temporary storage of the salt water, - a first pipe and a second pipe provided with respective closing means (21, 22) and designed to put in fluid connection the first tank and the second tank; - at least one hydroelectric turbine, acting along the first pipe and activated by the flow of water along the first pipe, for converting kinetic energy into electricity; - at least one pumping unit, acting along the second pipe and which can be activated for transferring the salt water from the second tank to the first tank; - a photovoltaic apparatus designed to convert solar radiant energy into electricity; - a desalination apparatus, designed to be put in fluid connection with the second tank for receiving at least one portion of the salt water from the second tank and for separating the salt water into salt and water, thus making the salt and the water available, the first tank, the second tank, the desalination apparatus and the photovoltaic apparatus being housed in the same tower structure; - an apparatus for performing electrolysis, designed to be put in fluid connection with the desalination apparatus for receiving the water and performing the electrolysis of the water, separating the water into hydrogen and oxygen; - a control unit, designed for allowing a plant management operator to control activation/deactivation of the desalination apparatus, of the pumping unit, of the electrolysis apparatus and to control opening/closing of the above-mentioned closing means (21, 22).