Results about energy capture from the environment associated with the self-powering of a wireless sensor network (WSN) for structural health monitoring of aircrafts (SHM) are presented. Thermal gradients taking place during specific flight phases are converted into electrical energy by using a small water tank coupled to a thermoelectric generator which output is connected to a storage circuit. The proposed system is experimentally assessed in an environmental chamber. Regarding the energy storage issue, considering the operating temperature (-55°C) and the amount of energy, supercapacitors are suggested instead of batteries. For capacitors charging and later use of energy, a circuit based on a voltage booster associated with a DC-DC regulator is designed and simulated.