| abstract |
A solid oxide fuel cell capable of increasing overall energy efficiency while preventing excessive temperature increases is provided. The present invention is a solid oxide fuel cell (1), and comprises: a fuel cell module (2); a fuel supply means (38); a means for supplying an oxidant gas for generating power (45); a thermal storage material (7); and a control means (110) that implements control on the basis of the demand for power, such that the fuel utilization rate is high when the generated output is large, and low when small, and that changes the power that is actually output, in a delayed manner, after the amount of fuel that is supplied has been changed. The control means: is provided with a means for estimating the amount of stored heat (110b), which estimates the amount of surplus heat on the basis of the fuel supply and the power to be output in a delayed manner with respect to the fuel supply; and is characterized in that when the means for estimating the amount of stored heat estimates that a usable quantity of heat has accumulated in the thermal storage material, the amount of fuel supplied is reduced in such a manner that the fuel utilization rate increases with respect to the same generated output. |