NOVELTY - A fuel cell system has a power load controller which performs a rapid load recovery procedure by controlling power output of the fuel cell system to increase from a power output corresponding to the low load to the high target power output corresponding to the high load at a higher rate than during a standard load recovery procedure.    USE - For use as high temperature fuel cell systems, such as molten carbonate fuel cells (MCFCs) and solid oxide fuel cells (SOFCs).    ADVANTAGE - The rapid load recovery procedure allows the fuel cell system to recover to high power output operation in a shorter time period than if the standard load recovery procedure is employed. This increases the efficiency and power production by the fuel cell system, and does not allow the fuel cell system to cool significantly. The rapid load recovery minimizes thermal and mechanical stresses on the fuel cell stack and does not result in damage to the stack.    DETAILED DESCRIPTION - The fuel cell system has a power load controller for controlling a power output on the fuel cell system based on a power output set point. If the load drops from a high load to a low load and the ability to ramp to a high target power output is then restored, the controller performs a rapid load recovery procedure by controlling the power output of the fuel cell system to increase from a power output corresponding to the low load to the high target power output corresponding to the high load at a first predetermined rate (e.g., 50 kW/minute) if all of one or more predetermined conditions are satisfied; and the controller performs a standard load recovery procedure by controlling the power output to increase to the high target power output at a second predetermined rate (e.g., 0.5 kW/minute) if at least one of the predetermined conditions is not satisfied. The first predetermined rate is greater than the second predetermined rate. The fuel cell system is connected to or independent of a power grid. The high load is at least 10 kW greater than the low load and the load drop is an instantaneous load drop from the high load to the low load over a time period of less than or equal to10 seconds. The fuel cell system receives input fuel, input water and input oxidant. INDEPENDENT CLAIMS are included for:    (1) method of operating a fuel cell system; and    (2) programmed computer controller and program on a computer readable medium for carrying the method.    DESCRIPTION OF DRAWING(S) - The figure shows a fuel cell system employing a load control assembly for controlling power output of the system and for performing rapid load recovery.