Abstract: The present invention comprises a system for use of fuel cells in stationary/mobile devices with a stable/unstable load profile, having: a fuel cell; a buffer for storage of surplus energy arranged to function as a regulating system between the fuel cell and energy consumption unit; a dumping device for dumping of energy when the buffer is full or according to need; an energy generator/converter for transforming energy when required to another form of energy, at larger energy demand than the fuel cell can meet, or for transforming of energy which is not used and which shall be stored in another form, or for transforming of energy which is stored in the buffer which shall be dumped in another form; and a procedure for use thereof.