Piezoelectric Wind-energy-harvesting Device With Reed And Resonant Cavity

Energy harvesting devices scavenge the ambient energy to power portable electronics or wireless sensor nodes, without the use of traditional batteries, which have limited lifespan. Harvesting energy from ambient vibrations has wide potential application, and has recently attracted much attention. There are two main approaches that can be used to scavenge wind energy: piezoelectric and electromagnetic. In this paper use the piezoelectric generators to harvest the wind energy. Piezoelectric generators employ the piezoelectric effect, convert to e directly.Piezoelectric wind-energy-harvesting device firstly converts the wind energy to vibration energy using a mechanism,then convert the mechanical energy to electrical energy with the piezoelectric material. Many wind-energy-harvesting devices have been created utilizing the rotation mechanism. But they have many disadvantages: complex structures,short life and low energy conversion efficiency.This letter reports a new wind energy harvesting device using a piezoelectric element and a mechanical resonant cavity which is similar to the structure used in harmonica. Under the help of the resonant cavity, the reed vibrates efficiently and a piezoelectric element stuck on the reed generates electricity accordingly. The dimension of the wind inlet is about 3cm×2cm. The device was investigated in the wind with a speed ranging from 6.4 MPH to 22 MPH, and an output power of 0.5mW to 4.5 mW can be got with a matching load of 0.46MΩaround this wind speed range. The energy conversion efficiency of the device can reach up to 2.4%.