Contact-less wind turbine utilizing piezoelectric bimorphs with magnetic actuation

The demand for efficient small-scale wind harvester is continually increasing in order to meet the local power needs for applications ranging from wireless sensor networks to charging of mobile devices. The efficiency of wind turbines is dependent upon several structural variables including factional contacts. In order to overcome the problem of gearing and losses in mechanical contacts, we propose here a novel small-scale windmill design that utilizes magnetic attractive and repulsive force to create mechanical oscillation in piezoelectric bimorphs which is then converted into electric charge through direct piezoelectric effect. This contact-less wind turbine has several advantages including operation at much lower wind speeds and longer life span. The prototype was fabricated as a vertical-axis wind turbine featuring a modular Sarvonius rotor. Characterization was performed by utilizing several configurations for this modular rotor. Output power magnitude for steady-state operation in wind speeds of 2-10 mph was used to compare the performance of various configurations.