Method to generate hydrogen by means of electrolysis, wherein water is fed to at least one electrolyzer, and then hydrogen is generated in the electrolyzer by means of electrolysis, wherein prepared water is taken from a water supply, and/or salt water, or brackish water, or sweet water is taken from a saltwater, or brackish water, or sweetwater source and fed as fresh water to a carrier gas stream such that the fresh water is taken up at least partially in an evaporated form therein and is fed as a carrier gas stream charged with steam to the at least one electrolyzer in which hydrogen, or hydrogen and oxygen, are removed from the carrier gas, wherein the carrier gas is guided in a carrier gas circuit, and after the hydrogen, or hydrogen and oxygen, are removed, said carrier gas is then returned indirectly or directly to the carrier gas circuit, the fresh water supplied to the carrier gas stream and entrained therein at least partially in an evaporated form is supplied as a carrier gas/steam mixture to at least one compressor by means of which it is brought to a temperature such that there is a hot steam/carrier gas stream, the fresh water is supplied for preheating to at least one preheating device (16, 20, 30) in which the fresh water is preheated to a specific temperature below the evaporation or boiling temperature of fresh water depending on the predominating pressure such that part of the fresh water sprayed very finely into or supplied to the carrier gas stream evaporates substantially immediately or directly after being supplied and forms a wet carrier gas/steam mixture with the dry carrier gas stream, the wet carrier gas/steam mixture is supplied to at least one carrier gas/steam mixture heat exchanger by means of which the wet carrier gas/steam mixture is superheated such that a superheated carrier gas/steam mixture is generated that contains a specific residual water component, the superheated carrier gas/steam mixture having a residual water component is supplied to a concentrate separator in which the residual water component is separated together with the salts dissolved therein as a concentrate, the dry carrier gas/dry steam mixture leaving the concentrate separator is compressed to a specific pressure by means of the least one compressor while simultaneously undergoing an increase in temperature, and supplied to the at least one carrier gas/steam mixture heat exchanger in which at least part of the steam condenses, wherein the at least partially condensed carrier gas/dry steam mixture is then supplied to a condensate separator in which the arising condensate is separated, and a moist carrier gas is obtained that is supplied to the at least one electrolyzer, before being supplied to the carrier gas circuit and before being preheated, the fresh water is supplied to a pump receiver that is upstream from at least one pump conveying the fresh water to the carrier gas circuit, and that is assigned a control device by means of which the supply of fresh water into the pump receiver and/or the removal of fresh water from the pump receiver is regulated, characterized in that the condensate arising in the condensate separator is supplied indirectly to the pump receiver such that the condensate arising in the condensate separator, before being supplied to the pump receiver, is supplied for exchanging heat to the preheating device in which the fresh water is preheated to a specific temperature below the boiling temperature of fresh water, before being supplied to the pump receiver and after the preheating device, the condensate arising in the condensate separator is supplied to a relaxation device in which pressure is decreased, and the energy for operating power consumers of the system is at least partially provided by means of a turbine that drives a generator and is in the condensate drain line coming from the condensate separator.