Battery-powered IoT devices incur significant maintenance cost and complexity in remote and large-scale environmental monitoring deployments due to regular battery replacement. Energy harvesting in combination with supercapacitor charge storage offers a promising solution, but practical deployments are few and far between. This paper contributes to application research in this space by presenting an experience report on deploying a battery-free sensing system for wireless monitoring of forest microclimates. Our approach combines adaptive power management hardware and intelligent scheduling algorithms, which are compared against a baseline rechargeable battery-based solar alternative. In both cases, the wireless devices are used to drive a sensing system that reports atmospheric pressure, temperature, humidity, air quality and light levels over the LoRaWAN network. This data is used by environmental scientists to study and better understand the forest ecosystem. We evaluate our battery-free approach against the battery-powered baseline in a two-month forest monitoring deployment, demonstrating reliable operation using only harvested energy, while highlighting important lessons learned for researchers and practitioners deploying battery-free sensing systems.

Most Internet of Things (IoT) devices rely on batteries with operational lifetimes of only a few years, resulting in high maintenance costs and significant environmental impact from battery waste. Energy harvesting (EH) combined with supercapacitor-based energy storage has emerged as a promising alternative, enabling longer-lived and more sustainable IoT systems. However, the design and deployment of such battery-free systems remain challenging due to their complexity and perceived unreliability. To overcome these barriers, we present Flute, a plug-and-play (PnP), battery-free IoT platform designed for remote sensing applications. Flute integrates energy harvesting, supercapacitor storage, and NB-IoT connectivity to enable autonomous long-term operation. In this paper, we demonstrate Flute’s capabilities through a contactless waterlevel sensing application, highlighting its potential to simplify the development and deployment of sustainable IoT systems.

The short lifespan of conventional smartphone batteries leads to toxic waste and increases replacement costs. In addition, contemporary devices require reliable electrical infrastructure which remains unavailable in major parts of the developing world. To address these problems, we propose a BAttery-free Mobile Interactive device (BaMbI), which aims to offer a scaled down set of smartphone features. BaMbI is based around an ARM Cortex M33 module with integrated LTE-M. In place of a battery, BaMbI uses a solar panel and an array of super-capacitors that offer sustainable operation and that can be fully charged in under one minute when mains power becomes available.