A Novel Thermoelectric Energy Harvester for Wireless Sensor Network Application

Sensor-based application of environmental monitoring has a huge potential but the only limiting factor is that it is battery operated and thus energy constraint. Energy harvesting is a boon as it helps in environmental monitoring applications. Thermoelectric energy harvesting (TEH) has been explored by researchers and they have proposed the various architecture of TEH systems. The temperature difference is the critical factor for developing TEH system as it directly affects the output energy of the system. In this paper, a novel thermoelectric energy harvester is proposed for wireless sensor network (WSN) based environmental monitoring application, which considers the change in temperature in a cyclic manner. Phase change material (PCM) used is of high latent heat and an intelligent algorithm is proposed that manages the heat energy and maintain the temperature gradient up to 2 ^{\circ }C. This results in heat flow in interchangeable orders during day and night, thus improving the overall output electrical energy. The intelligent algorithm and optimized framework of TEH system considering parameters affecting TEH facilitates the maintenance of \Delta T. The system is fabricated and implemented using water as PCM. The overall energy output achieved is 10.23 J/g, which is sufficient to achieve a perpetual lifetime of WSN-based environmental monitoring systems.