Geothermal electricity generator using thermoelectric module for IoT monitoring

Abstract

We propose a power generation system for IoT monitoring, using thermoelectric generator (TEG) modules and geothermal heat sources. Moreover, optimal conditions to operate the system for a hot spring in Thailand were investigated as a case study, i.e., feasibility study for utilization of geothermal energy as renewable energy. The aggregated TEG module was installed in the heat transfer channel soaked into a hot water bath. The generated power was used to supply the Internet of things (IoT) system for hot-spring monitoring. The IoT system was connected to sensors of temperature, humidity, and sulfur dioxide (SO2) to monitor and collect the information of the hot spring. The information can be monitored on mobile phones via the application. Twenty TEG modules were installed in the heat transfer channel. The heat sinks were used to transfer the heat while soaking into the hot water bath. By using the IoT system, data of the hot-spring monitoring was collected on cloud backup. The results show that the power outputs increase relating to the increase of the temperature gradient. The correlations between the power output and the hot water bathing temperatures were reported. The IoT system can collect information of hot-spring monitoring properly. It can be suggested from these features that energy recovery from the hot spring using TEG could be a potential source of renewable energy for the IoT system.