Hybrid Solar–RF Energy Harvesting Architecture for Self-Sustaining Wireless Sensor Networks

Abstract

This study offers a solar-RF energy harvesting architecture merger that is expected to address the energy constraints in Wireless Sensor Networks (WSNs) that relies on batteries as well as support unlimited, self-sustaining functions. The system combines high-power density photovoltaic cells with ubiquitous low-power radio frequency (RF) rectennas to allow the system to overcome intermittent behaviour of single sources in the ambient environment and therefore to provide a continuous power stream even at night-time or indoor environments. The key idea behind such architecture is a dynamic duty cycling algorithm controlled under the principals of Energy-Neutral Operation (ENO) that adjusts the active and sleep mode of sensor node depending on the real-time state-of-charge of a supercapacitor buffer. Test data confirms that the energy harvesting efficiency (η) has been increased significantly and there is a constant voltage profile that is not below operational levels, at 24-hour cycles. This two-source declaration decelerates the stochastic power inflow combined with optimised power usage to produce a scalable remedy to long-term IoT systems in remote or inaccessible areas that is maintenance-free.