An arc-shaped piezoelectric generator for multi-directional wind energy harvesting

In this study, a piezoelectric wind energy harvester was demonstrated, which aimed at addressing the limitations of the existing approaches including single-directional operation and narrow working wind speed range. In the harvester, an arc-shaped elastic beam, instead of conventional thin cantilever beams, was adopted to extract wind energy. Benefiting from the beam's characteristics of arc-shaped structure and elasticity, the harvester is capable of scavenging wind energy without any extra accessory and responding to multi-directional wind excitations. An analytical model was established to investigate the effects of wind direction and structural parameters on the electrical output. In test, the harvester worked efficiently with wind coming from four directions in a speed range of 2-17 m/s and produced a maximum open-circuit voltage up to 34 V. When connected to an external load of 15 kΩ, the harvester showed a peak output power of 1.73 mW at 17 m/s. In addition, 18 serial-connected commercial light-emitting diodes (LEDs) were lit up simultaneously at the wind speed of 10.5 m/s, which confirmed the practicability of the harvester.