A wind energy harvester for low power wireless sensor networks

At present a lot of research is being done to find alternative methods of powering up wireless sensor networks (WSN) in order to increase the lifespan of these networks. Due to large efforts the power consumptions of these sensors are continuously being improved to operate in the milliwatt and microwatt range, therefore making renewable energy suitable for this application. In this paper a wind energy harvester (WEH) was designed, built, and tested to determine if wind energy is viable for supplying power to WSN´s. The WEH consisted of a wind generator and a power management unit to store and condition the generated energy. The wind generator designed utilizes aero - elastic flutter to convert wind energy into electrical energy, and is similar to the Windbelt that was developed by humdinger wind energy [2]. The wind generator consisted of a frame to hold components of the generator together, a membrane to convert wind energy in to mechanical energy, and an electromagnetic transducer to convert the mechanical energy in to electrical energy. The results show that the wind generator is operational at wind speeds of 2-9m/s, and is capable of supplying 70mW of power, and thereby making it extremely possible to increase the lifespan of a WSN. The power management unit consisted of the conventional diode bridge rectifier without maximum power point tracking (MPPT) resulting in poor efficiencies of the WEH.