A Two-Body Low-Frequency Piezoelectric Wind Energy Harvester for Environmental Sensing

This paper investigates a novel Two-body Piezoelectric Wind Energy Harvester (TbPE-WEH) designed to generate voltage from wind-induced vibrations. The harvester consists of a flat plate (bluff body) attached to the free end of a piezoelectric cantilever beam. A description of the energy harvester and experimental setup is provided, explaining the output voltage generation for a range of wind speeds. The study investigates the system dynamics using experimental modal analysis, which reveals the natural frequencies of the system. The activation of system nonlinearities causes a noticeable shift in the frequency content as the wind speed varies. At high wind speeds, the harvester appears to propel into limit cycle oscillations (LCOs), exhibiting self-sustained motion caused by aerodynamic instabilities. This novel two-degree-of-freedom vibration energy harvester design may harness wind energy over a wide speed range by gaining large oscillations as compared to the vibration energy harvesters operating under aerodynamic instabilities that are presented in the literature. A maximum open circuit voltage of approximately 6–7 V is achieved by this non-optimised energy harvester prototype.