Electrolyser System

A method of operating an electrolyser system, the electrolyser system comprising:

• a) at least one electrolyser, the electrolyser comprising at least one steam inlet and at least one off-gas outlet, the electrolyser having an operating pressure;
• and
• b) a turbocharger for compressing off-gas from the electrolyser, the turbocharger comprising a drive fluid inlet, a drive fluid outlet, a compression fluid inlet, a compressed fluid outlet, a compressor and a turbine,
• wherein:
• steam at a supply pressure that is higher than the operating pressure of the electrolyser is provided to the drive fluid inlet of the turbocharger to power the turbine, which turbine is configured to drive the compressor;
• the drive fluid outlet of the turbocharger is fluidically connected to the at least one steam inlet of the electrolyser, whereby the steam then exits the turbine and enters the electrolyser at a reduced pressure compared to its supply pressure;
• and
• the at least one off-gas outlet of the electrolyser is fluidically connected to the compression fluid inlet of the turbocharger, whereby off-gas from the electrolyser fees to the turbocharger for compression by the turbocharger.