Design Concept of Adjustable Thermoelectric Generators Comprising Multiple Thermoelectric Modules: Output Power and Internal Resistance Control

This paper reports on a design concept for an adjustable thermoelectric generator (TEG) comprising multiple thermoelectric (TE) modules. This TEG allows for controlling the output power and internal resistance of the TEG by adjusting the number of TE modules connected. First, plate‐type TE modules were fabricated by depositing an Al layer on a Fe plate (using easily available materials). TEGs were fabricated by connecting up to eight modules by alligator clips, and the TE performance of TEGs with different numbers of modules was evaluated. It was verified experimentally that the Seebeck coefficient of the TEGs increased in proportion to the number of TE modules. However, the maximum output power did not do so due to the high connection resistance of the alligator clips. Next, the connection resistance between Fe and Al plates was measured when the plates were stacked in various ways and found that Cu plates (sandwiched between the plates and fixed with a jig) realized low connection resistance. Based on the above experimental results, the relationships between TE performance of the TEGs and the number of TE modules connected were predicted by a theoretical model considering the connection resistance between TE modules. This paper introduces the design concept of a TEG, which controls output power and internal resistance by adjusting the number of TE modules to take into account the resistance of the device being powered.