Proposal of Wind Vibrational Power Generator Using Magnetostrictive Material

Wind turbine is the most effective power generation device. However, it works efficiently only in large-scale applications. Recent technological advancements in renewables and energy generation focus on harvesting kinetic energy from low-speed winds in much smaller regions, such as air-conditioning ducts. In this paper, we propose a simple wind vibrational power generator that utilizes magnetostrictive material to harvest electrical energy from low-speed wind. Magnetostrictive materials undergo large variations in magnetic flux upon the application of external force, such by wind-induced vibration, generating electromotive force. Our vibration power generator uses an iron-gallium (Fe-Ga) alloy, which has extremely high sensitivity and energy conversion efficiency. Through a wind tunnel experiment, the generator was confirmed to be suitable for power generation from low wind-speed regimes, such as air-conditioning ducts. The device used a wind receiving part made of a thin rectangular plate of polylactic acid (PLA) resin and a power generating part. It was achieved by passing a stream of wind around the plate to produce a vortex in its wake region and induce a cross-flow vibration, in which the device sensed and converted into electrical energy. In essence, vortex excitation helped in generating power even at near streamlined flow.