Energy Harvesting for Wireless IoT Use Cases: A Generic Feasibility Model and Tradeoff Study

Abstract

A batteryless Internet of Things (IoT) offers a sustainable alternative to battery-powered IoT devices, which produce billions of dead batteries every year. Devices are instead powered by a small supercapacitor, which is recharged by a renewable energy source. However, since IoT devices are often characterized by intermittent periods of high energy consumption followed by periods of reduced activity, conventional average energy consumption models cannot be used to assess if IoT devices can be powered by energy harvesters. Therefore, this article presents an alternative feasibility evaluation approach that focuses on modeling the worst case periods with peak energy consumption and short idle times, which pose the highest constraints on the capacitor's behavior. This approach simplifies the characterization of the wireless technology energy consumption as these worst case periods can be determined by a few parameters. The methodology is then applied to combinations of popular IoT technologies (LoRaWAN, BLE Mesh, and 6TiSCH) and energy sources (solar, kinetic, and radio frequency energy) for two common IoT use cases. We show that the proposed parameters can be successfully extracted with power measurements for different network configurations and that the Power Management Unit configuration has a nonnegligible impact on the communication requirements. Finally, we discuss how to apply the model to other technologies and other use cases.