A polymer electrolyte membrane fuel cell (PEMFC) system is developed to power a notebook computer. The system consists of a compact methanol-reforming system with a CO preferential oxidation unit, a 16-cell PEMFC stack, and a control unit for the management of the system with a d.c.–d.c. converter. The compact fuel-processor system (260cm3) generates about 1.2Lmin−1 of reformate, which corresponds to 35We, with a low CO concentration (<30ppm, typically 0ppm), and is thus proven to be capable of being targetted at notebook computers.