A portable computing device such as a laptop computer has a base unit (2) and a display screen unit (3) coupled together by a hinge assembly (7) configured to allow rotation of the base unit and the screen unit relative to one another. The display screen unit has a display panel on a first face of the display screen unit and a fuel cell array (12a, 12b) disposed adjacent to a second face of the display screen unit. Ventilation apertures through the second face of the display screen unit provide air flow to the fuel cell array. A fuel conduit extends between the base unit and the display screen unit across the hinge assembly for delivering fuel from the base unit to the display screen unit.