The objective of this work is to develop control techniques for the efficient operation of fuel cells generating electric power. The system to be controlled consists of a network of multiple fuel cells. The proposed control system structure is a multilevel implementation. The first level deals with dedicated feedback control to keep the parameters of a cell at set-point values with minimized error. The desired values (set points) of feedback controls are adjusted by supervisory controls corresponding to a minimized energy production cost. The dynamics and the steady performance of a cell are utilized to determine the first-level control functions. The operational values of performance parameters such as conversion factor, efficiency, cell potential, power density, fuel utilization, temperature, current, electrolyte concentration, and power are determined to arrive at an overall maximum efficiency and minimum operational cost.