Design and Optimization of a Novel, Low-cost, Compact Wind Power Generator for Autonomous Environmental Sensing

Abstract

This research responds to the vision that sensors connected to an Internet of Things (IoT) can be used to wirelessly monitor the built and natural environments— especially in developing nations—promoting, in turn, sustainable practices such as frugal energy use and pollution control. While small solar panels can supply power to state-of-the-art sensors which can be operated with as little as 0.1mW, wind power is an important alternative for sensors that must operate in the shade, at night, or in indoor structures such as airducts. While wind is ubiquitous, research on efficient flow-based milliwatt-scale generators has only just begun. Our design concept is based on tapping the energy contained in the turbulence that results when a flat surface obstructs a fast-moving airflow. Using preliminary experimentation, we determined that a triangular prism, attached to a cantilevered flexible beam is suitable for extracting power from the flexure of a piezoelectric piece attached to the beam. We varied the beam and prism dimensions and identified parameter ranges that yielded optimal performance. We obtained over 0.5mW of average power with a device consisting of a 12.5cm beam, and prism with face dimensions of 10cmX6.5cm at modest wind speeds.