The present invention concerns an electrolysis system for high temperature electrolysis including a plurality of flow-based electrolysis units configured to receive an electrolyte solution and to perform electrolysis to provide a first output gas and a second output gas, the plurality of flow-based electrolysis units being membrane-less electrolysis units; at least one heating mechanism or means for heating the electrolyte solution to undergo electrolysis; a first gas separator and a second gas separator configured to remove the first output gas and the second output gas from the electrolyte solution; and an encasement or a cell enclosing the plurality of flow-based electrolysis units, the encasement or the cell being configured to support a pressure of the electrolyte solution permitting to increase a boiling point of the electrolyte solution to a temperature between 96°C and 350°C.