Unification criteria of optimization and energetic analysis of a thermoelectric–generator

Thermoelectric generators have been of great interest in recent years; however, these studies have focused on maximum power output and maximum efficiency modes of operation. In this work, an analysis is presented under different modes of operation studied within finite-time thermodynamics (FTT), so it is possible to describe in a broader way the energetic of this type of thermoelectric converters. This analysis will be approached from the point of view of a recent work by Gonzalez-Hernandez (2020), based on a set of dimensionless variables. Obtaining a unification criterion for the study of thermoelectric refrigerator and heaters through the figure of merit y and the optimization of a single dimensionless parameter x from the point of view of the FTT. In this case, the figure of merit limits the maximum value of the modes of operation to an optimal range. Among other results, it should be noted that some materials will not reach the maximum efficiency of 2/3, regardless of the value of the figure of merit. •Unification of optimization criteria for thermoelectric generators.•Comparison of modes of operation.•Functional control region for thermoelectric systems.•Optimal values of the figure of merit, within the Functional Control Region.