Effect of electrical array configuration of thermoelectric modules on waste heat recovery of thermoelectric generator

An experimental study was undertaken to investigate the effect of the electrical array configuration of thermoelectric modules (TEMs) on thermoelectric power generation. A thermoelectric generator (TEG) was constructed with customized TEMs. Prior to the system-wise power generation experiment, the electrical characteristics of each TEM (a total of ten TEMs) were measured. The sum power output of each TEM was 34.2 W, which was set as a reference power output for different system-wise array configuration methods To examine the effect of the array configuration, eight different TEM array configurations were formed using series, parallel, and combination connections to provide different power sources for different applications. The experimental results showed that the system-wise power output of the different array configurations varied up to 59% compared to the reference power. Moreover, a 1.4–36.4% difference in power output was evident compared to the individual array configuration on account of the different ways in which the TEMs were electrically connected. The number of junctions in the circuitry and the unbalanced number of modules in the array configuration were chosen as the possible parameters that mostly affected the power output in various electrical circuitries for a constant temperature difference across the TEM sides. Consequently, the power output of the TEG decreased with the increasing number of circuitry junctions in the TEG. The array configuration with less than two junctions in its circuitry showed a power generation up to 94%, whereas the array configuration with six junctions generated only up to 62.5% compared to the reference power output. Similarly, the power output of the TEG decreased with the increasing unbalanced number of modules in the circuitry. The power generation of TEG array configurations with a balanced number of modules in the array was up to 95.4%, whereas that with four unbalanced number of modules in the array only generated 58.9% compared to the reference power output. Therefore, the array configuration with a minimized number of junctions and balanced number of modules is recommended for maximizing the TEG power output.