Patent ID: 7323268

Claim:
A power source with SOFC fuel cells, including the following components: a multi-modular unit formed with the fuel cells as modules, the volume of which is less than 10 3 m 3 , a channel system comprising a first kind of channels by which reactants, namely gaseous fuel and also air, can be fed to the fuel cells and a second kind of channels by which the partially depleted fuel can be discharged from the fuel cell and which second kind of channels is acting as an afterburner stage for the partially depleted fuel, a casing, which is at least partially made heat insulating, a heat exchanger which is part of the channel system and in which the air supplied can be heated up with exhaust gas, an apparatus or means for feeding the air, an exchangeable or refillable reservoir for the fuel, in which reservoir the fuel is stored at a pressure which is greater than a pressure present at the exterior of the power source and in which the fuel is preferably liquid, controlled valves in connection lines for the reactants, and a control, wherein the fuel cells respectively contain a disc-shaped solid electrolyte, which in addition to ion conducting components also includes electron conducting components which cause an ohmic loss and wherein the ratio of the ion conducting components to the electron conducting components is so designed that in an idling operation of the power source a heat flow from the cells to an environment can be compensated by the ohmic loss.