Characterization Of Thermoelectric For Energy Harvesting On Low-Level Heat Sources

Electric power harvesting from thermal energy using thermoelectric (TE) has been getting popular as a potential electrical energy source to replace batteries due to its direct current output. The focus of this paper is on the investigation of low level thermal energy below 150C that generated from electronic devices and mechanical machinery, and using TE’s to convert the heat energy, which normally treated as wasted energy into a useful amount of electrical power to power up portable low power electronic devices. For this study, the TE module is subjected to a range of heat source using heating element that resemble the real temperature that generated from the real electronic devices and mechanical machinery. The quantity of harvested electrical power was reported. From the experimental results it can be observe that the voltage output is linearity proportion to the applied heat gradient on the TE faces. At a temperature gradient of 60 C, a voltage output of 4 V is measured. The voltage output can be increased by stacking the TE on top of each other, from 0.067V/ C for 1 TE to 0.093V/ C for 4 TE

APPLICATION OF THERMAL ENERGY HARVESTING IN POWERING WSN NODE WITH EVENT-PRIORITY-DRIVEN DISSEMINATION ALGORITHM FOR IOT APPLICATIONS

Energy Harvesting (EH) has become a crucial part of self-powered autonomous systems, particularly for Wireless Sensor Network (WSN) nodes and the Internet of Things (IoT) sensors. The main advantages of exploiting Energy Harvesting approach lies on its portability, scalability, and low maintenance, as it reduces the dependency on batteries, therefore offers a sustainable and long-term solution for wireless monitoring over a wide area and a large number of sensor nodes. This paper discusses the use of Thermal Energy Harvesting (TEH) approach to power up a wireless sensor node for IoT applications. Wireless node WSN_1_TEH consists of MEGA328P as the main MCU, nRF24L01 wireless module, and DHT22 sensor. The TEH system consists of two thermoelectric generators with DC-DC boost converter based on MAX757 and an 8200µF storage capacitor. In the experiment, the TEH system was set to function as the only power source for the sensor node; for comparison of its performance with a 7.4 V rechargeable lithium polymer battery-powered counterpart, by operating for 40 hours continuously. In order to reduce power consumption, the WSN_1_TEH node was equipped with an energy-aware EventPriority-Driven Dissemination algorithm. It was developed to manage the WSN_1_TEH operation and to make the sink station able to detect a missing wireless node within the network, which will guarantee the nodes integrity detection. This algorithm will send out data packet based on event or priority, every 20 s of sleeping period. Besides power saving, it also reduces the overall network traffic. Based on the findings, the overall power consumption of this node is 39 mW in “active with transmission” mode, 28-32 mW in “active without transmission” mode, and only 23 mW when operating in “sleep” mode