Analysis of energy harvesting from multiple sources for wireless sensor networks with focus on impedance matching

Abstract

Multiple energy harvesting system architecture combining energy from solar, thermal and vibration sources is presented, with the configurable impedance matching features is to be analyzed. The system consists of maximum power point tracking mechanism. The system can handle the input voltage from 20mV to 5V from three distinct energy harvesting sources. The matching load is individually tuned for photovoltaic, thermoelectric and piezoelectric. Analog driving scheme and ultra low power components make the Power efficiency not less than 85%, 40% and 60% of the circuit voltage respectively. The intermediate storage element such as lithium batteries and super capacitor of 3.3V is used. The time it takes to fully charge up to 3.3 V with the rate of charging is 1.8 mV/sec.