Self-Supplying Photovoltaic–Hygroelectric Coupling System Powering Internet of Things Sensors

The rapid advancement in the Internet of Things (IoT) has prompted a proliferation of sensor applications with increasing focus on harnessing environmental energy sources for powering these sensors. However, owing to the variability inherent in climatic and geographic conditions, a singular approach to environmental energy harvesting often fails to deliver sustainable and reliable power. Hygroelectric technology, leveraging the electrical coupling between nanostructured materials and water to convert moisture-derived energy into electricity, complements the advantages of light energy collection technology. In this study, an ion diode moisture-based power generation array was fabricated to yield an open-circuit voltage of 8 V and a short-circuit current of 3 mA under an 86.9% relative humidity (RH). Subsequently, integration of a photovoltaic module with the hygroelectric generator assembly via an energy management circuit augmented the system's overall power generation, manifesting a remarkable 1150% increase over the original moisture-based power generation configuration. Furthermore, the incorporation of such a hybridized system bolstered the operational efficiency, extending the duration of continuous power supply cycles by up to 78.2% in comparison with the control group with no moisture-derived energy input. This pioneering endeavor unveils a novel light-moisture coupling energy-harvesting paradigm tailored for sustaining uninterrupted power provision in wireless sensor network nodes, and the harvesting of one energy source is not affected by the other energy source at all. With its inherent adaptability, this approach holds promise for deployment in outdoor environments characterized by low illumination levels and high humidity, presenting a versatile solution to address sensor powering challenges.