The present invention relates to a method for producing hydrogen in a polymer electrolyte membrane (PEM) water electrolyser cell. A direct electric current is applied to the water electrolyser cell. Water molecules are allowed to diffuse from a cathode compartment through a polymer electrolyte membrane into an anode compartment, to oxidize water molecules at an anode catalyst layer into protons, oxygen and electrons. The protons are allowed to migrate through a polymer electrolyte membrane into the cathode compartment and the protons are reduced at a cathode catalyst layer to produce hydrogen. The cell is supplied with water to the cathode compartment, and humidified air is supplied to the anode compartment. The invention also relates to a polymer electrolyte membrane (PEM) water electrolyser cell, a polymer electrolyte membrane (PEM) water electrolyser stack and a polymer electrolyte membrane (PEM) water electrolyser system.