An Overview On State-of-Art Energy Harvesting Techniques and Choice Criteria: a WSN Node for Goods Transport and Storage Powered by a Smart Solar- Based EH System

Abstract

This paper describes a solar-based harvesting system able to properly power supply the sensor node of a Wireless Sensor Network (WSN) developed for ensuring traceability and services relatively to goods stored in containers placed in the monitored areas (e.g commercial seaport). Battery life-time is a main problem especially in networks where sensor nodes are not easily accessible. For this reason, sensor nodes are equipped with power management devices able to supply power, in an intelligent way, from the harvester when harvestable energy is available or from backup batteries, ensuring, under every operating conditions, the correct functioning of node. In this research work, an overview of the available energy harvesting technologies, showing some related devices present on the market, is presented; subsequently, the suitable energy harvesting technique for power supply the designed WSN node was chosen. Hence the smart node able to monitor the physical parameters deemed of interest related to stored goods and a solar-based harvesting board, based on LTC3330 IC, were designed and tested. Supercapacitors are charged when harvestable energy is higher than the one required from node; stored energy is then used in time periods with no harvestable energy before requiring the backup battery intervention.