First study on harvesting wind energy using hybrid piezo-pyroelectric nanogenerator

This work describes a novel small wind energy harvesting process. The source of energy consists of the wind flow and vortex generator, and the harvester is composed by piezoelectric cell, pyroelectric cell, and full rectifier circuit. The mechanism of wind flow and the vortex generator produce both mechanical vibration and temperature change. We have demonstrated that we can convert simultaneously this vibration and temperature change caused by the wind and the vortex generator into useful electrical energy to power small electronic devices. In fact, the piezoelectric cell submitted to variable vibration produce current and temperature variation applied to pyroelectric cell produce also current. Experimentally, we have used 9 mu m flexible PVDF film which has piezoelectric and pyroelectric properties to design the two cells and the measurement was conducted in accredited ISO/IEC 17,025 wind tunnel. Thus, our hybrid and pyro-piezoelectric nanogenerator PPNG was able to produce exploitable power from 3 m/s to 36 m/s of wind velocity. The maximum power density was 6.4 mu W/cm2, which is comparable to recently developed nanogenerators. These results offer opportunities for self-powered devices on a very large scale of wind energy with less use of conventional batteries.