Development of a Self-Sufficient LoRaWAN Sensor Node with Flexible and Glass Dye-Sensitized Solar Cell Modules Harvesting Energy from Diffuse Low-Intensity Solar Radiation

Abstract

This paper aims to demonstrate the viability of energy harvesting for wide area wireless sensing systems based on dye-sensitized solar cells (DSSCs) under diffuse sunlight conditions, proving the feasibility of deploying autonomous sensor nodes even under unfavorable outdoor scenarios, such as during cloudy days, in the proximity of tall buildings, among the trees in a forest and during winter days in general. A flexible thin-film module and a glass thin-film module, both featuring an area smaller than an A4 sheet of paper, were initially characterized in diffuse solar light. Afterward, the protype sensor nodes were tested in a laboratory in two different working conditions, emulating outdoor sunlight in unfavorable lighting and weather to reconstruct a worst-case scenario. A Li-Po battery was employed as a power reserve for a long-range wide area network (LoRaWAN)-based sensor node that transmitted data every 8 h and every hour. To this end, an RFM95x LoRa module was used, while the node energy management was attained by exploiting a nano-power boost charger buck converter integrated circuit conceived for the nano-power harvesting from the light source and the managing of the battery charge and protection. A positive charge balance was demonstrated by monitoring the battery trend along two series of 6 and 9 days, thus allowing us to affirm that the system’s permanent energy self-sufficiency was guaranteed even in the worst-case lighting and weather scenario.

Piezoelectric Sensors as Energy Harvesters for Ultra Low-Power IoT Applications

“…Other authors, such as Olzhabay et al [ 5 ], have described an indoor IoT sensor node based on perovskite solar cells, demonstrating their ability to power low-power applications even under conditions of very low irradiance. Bruzzi et al [ 6 ] have investigated a typical LoRaWAN-based sensor node powered by dye-sensitized solar cells (DSSCs) under challenging conditions, showcasing the capacity of these devices to adequately supply power to the system even on cloudy days.…”

Graded-Index Active Layer for Efficiency Enhancement in Polymer Solar Cell

“…In recent years, the common advantages of all-polymer solar cells all-(PSCs), such as their lighter weight, flexibility, and the low-cost printing of for fabrication, have attracted significant interest [1][2][3]. At the same time, some methods have appeared that contribute to circumventing the challenges that have impeded improvements to the efficiency of solar cells that depend on semiconductors and methods for converting natural resources into electrical energy [4][5][6]. A layered PSC structure consists of at least a transparent front electrode, an active layer-which is the real semiconducting polymer material-and a back electrode fabricated on a plastic substrate.…”

Self-Sufficient Sensor Node Embedding 2D Visible Light Positioning through a Solar Cell Module

“…In particular, most of the applications exploit photovoltaic (PV) cells exposed to direct sunlight to provision energy for self-sufficient wireless sensor nodes [ 18 ]. However, there is a growing interest in the possibility of exploiting PV modules for energy harvesting also from diffused sunlight and from artificial light in indoor environments, both with white and colored spectrum [ 19 , 20 , 21 , 22 ].…”