Optimal Designs of Thermoelectric Generators for Supplying Maximum External Load

The operation of a thermoelectric generator (TEG) is a complicated multidisciplinary subject since it involves the phenomenon of electrical and thermal transport in a dependent manner. This paper focuses on determining the optimum electrical load resistance to be supplied by a given TEG system. Thermal exchanges and electrical transport were evaluated through existing mathematical tools. Our model using a computer program, considering the leg length as a variable parameter, revealed that the optimum geometric ratio is between the two most known values, 1 and (1 + ZT)1/2 where ZT is the dimensionless figure of merit of the TE couple. However, the found results revealed that these values regain validity for highly conductive fluid. In particular, we observed that high convection coefficients such as that of water tend to impose effective resistance as the optimum value of the external load resistance. Our results clarify the discrepancy between the various hypotheses partially proven in the literature.