Battery-Free Power Supply for Wireless Sensor Combining Photovoltaic Cells and Supercapacitors

Abstract

This article exhibits the sizing, modelling, and characterization of a power supply (output 3.3 V, 200 mA max, 11 days full autonomy) dedicated to powering a wireless sensor node without a battery but usable as simply as with a battery. This system is modular for various light levels (indoor and outdoor). It is easily integrable into a sensor node, using only commercial circuits. The choices of the photovoltaic surface (amorphous silicon, η 5%, 35 cm 2 ) and of the supercapacitors value (2x 25F, 2.7 V) are explained for permanent operation, considering the solar potential and the consumption. An original part of the paper is devoted to the issue of the startup, in which we demonstrate that after a particular preload, once installed, the device can start on request at the desired time (within 15 days) using as a trigger any light source, such as the LED of a mobile phone.

A Comprehensive Review and Analysis of Nanosensors for Structural Health Monitoring in Bridge Maintenance: Innovations, Challenges, and Future Perspectives

“…For embedded nanosensors, power can be supplied through batteries or energy harvesting techniques, such as solar cells or vibrational energy harvesters [83]. Batterypowered sensors offer mobility and independence from external power sources but require periodic maintenance and replacement [84]. Energy harvesting techniques utilize the ambient energy available in the bridge environment, such as vibration or sunlight, to generate power for the sensors.…”

Adaptive Algorithms for Batteryless LoRa-Based Sensors

“…However, these theoretical results, particularly [ 22 , 24 ], might be overly optimistic in terms of inter-arrival times between packets and the size of the storage capacitor, and require confirmation in real-world implementation. The studies [ 25 , 26 ] proposed some prototypes of batteryless nodes based on LoRa technology. Specifically, Orfei et al [ 25 ] demonstrated the performance of a batteryless sensor for monitoring road traffic and bridge conditions, powered by a low-cost electromagnetic EH device, which employs an array of permanent magnets to improve energy efficiency.…”

“…The collected energy is stored in a supercapacitor and powers an ARM Cortex M0+ microcontroller and a LoRa radio module to transmit information. On the other hand, Boitier et al [ 26 ] introduced a self-contained LoRa sensor with a photovoltaic power source and a pair of 25 F supercapacitors for energy storage. This solution assures 11 days of storage life in the absence of light.…”

Powering a Low Power Wireless Sensor in a Harsh Industrial Environment: Energy Recovery with a Thermoelectric Generator and Storage on Supercapacitors

“…An alternative solution we are considering is to harvest the available energy in the device's environment. Based on the conversion of ambient energy into electrical power, this approach has the potential to make IoT devices maintenance-free and permanently powered [3] [4]. In this case, the sensor node must include an energy storage block which provides the output power despite the intermittency and possible variations of the ambient available energy.…”