Self-powered water condition monitoring system based on rotational electromagnetic generator

As a widely available clean energy source in nature, water flow energy provides a research avenue for energy harvesting and environmental monitoring. This work proposes a self-powered water condition monitoring system based on rotational electromagnetic generator (WCM-EMG). The WCM-EMG adopts a fully enclosed design that collects energy by converting water flow into rotational motion, eventually generating electrical output based on electromagnetic induction. Through the optimization of impeller parameters, WCM-EMG can obtain higher electrical output with lower water head loss. At a flow velocity of 1.5 m/s and load resistance of 25 Ω, the WCM-EMG generates a power output of 606 mW and power density of 0.93 mW/cm³ while the head loss is only 2.5 m. For one thing, the WCM-EMG achieves a high-power supply for self-powering of the temperature, pH and turbidity sensors. For another, by processing the frequency of the electrical signal of WCM-EMG, the self-sensing of water flow velocity can be realized in real-time. By harvesting the kinetic energy of fluid flow, this work offers an encouraging solution for developing integrated multi-parameter intelligent sensing system that encompasses energy harvesting, self-sensing and monitoring, enabling passive zero-carbon sensing in the Internet of Things (IoT).