A Study on Miniature Wind Turbines for Application to Energy Harvesting

Abstract

Seven miniature models with the diameter of 80 mm based on the butterfly wind turbine that is a lift-driven type and vertical axis type and one cross-flow wind turbine model of a drag-driven type were built by a 3D printer. Experiments for the measurement of electric power generation by using DC-motors equipped with the wind turbine models were conducted. The rotational speed under a constant wind speed did not depend on neither the kinds of DC-motors as the electric generator nor the value of the electric load resistance; that is, the rotational speed was decided by the wind turbine shape. The maximum electric power (262.5 μW at 6 m/s) obtained in this study was produced by the butterfly wind turbine model with outward-cambered blades. Since the maximum efficiency is small (0.041 %), the selection or development of a better motor as a generator fitting to the wind turbine model would be needed.