Nowadays, energy management becomes an absolute necessity. To reduce systems consumption, the idea is to recover energy when it is possible and to reuse it when the system is in need. Energy can be saved in peak power unit (electric double layer capacitors called supercapacitors). Those latter can absorb or supply power peaks. This paper deals with the conception of hybrid power sources using fuel cell as main source, a DC link and supercapacitors as transient power source. The whole system is modeled in state space equations. The energy management is reached using Passivity-Based Control (PBC). PBC is a very powerful nonlinear technique dealing with important system information like the system's total energy. Stability proof and simulation results are given. In this proposed control laws only few measurement are needed (two or three depending on the presented solutions one or two). (C) 2010 Elsevier Ltd. All rights reserved.