Enhanced Efficiency of Thermoelectric Generator by Optimizing Mechanical and Electrical Structures

TLDR

Low‑temperature thermal resources are increasingly used for power generation, yet most commercial technologies convert heat to electricity indirectly, whereas thermoelectric generators (TEGs) can directly convert heat to electricity via the Seebeck effect, offering compactness, quietness, and reliability, but suffer from low thermal‑to‑electric efficiency. The authors redesigned and modified their previous 1 kW TEG system operating at a ~120 °C temperature difference to enhance its performance. They conducted laboratory experiments measuring output power under varying conditions—different TEG module connection modes, mechanical structures, and temperature differences—while redesigning the system’s mechanical and electrical architecture. The redesigned system achieved a 34.6 % increase in output power and an instantaneous efficiency of about 6.5 %, with the apparatus tested and data presented, indicating suitability for low‑temperature thermal and geothermal sites such as oil fields.

Abstract

Much attention has been paid to the application of low temperature thermal resources, especially for power generation in recent years. Most of the current commercialized thermal (including geothermal) power-generation technologies convert thermal energy to electric energy indirectly, that is, making mechanical work before producing electricity. Technology using a thermoelectric generator (TEG), however, can directly transform thermal energy into electricity through the Seebeck effect. TEG technology has many advantages such as compactness, quietness, and reliability because there are no moving parts. One of the biggest disadvantages of TEGs is the low efficiency from thermal to electric energy. For this reason, we redesigned and modified our previous 1 KW (at a temperature difference of around 120 °C) TEG system. The output power of the system was improved significantly, about 34.6% greater; the instantaneous efficiency of the TEG system could reach about 6.5%. Laboratory experiments have been conducted to measure the output power at different conditions: different connection modes between TEG modules, different mechanical structures, and different temperature differences between hot and cold sides. The TEG apparatus has been tested and the data have been presented. This kind of TEG power system can be applied in many thermal and geothermal sites with low temperature resources, including oil fields where fossil and geothermal energies are coproduced.