Simple thermodynamic modeling of heat engines as thermal gap systems provides useful insight on the performance of power plants. When a temperature difference exists, a potential for power production ensues, and optimization is naturally sought. When electric and/or thermoelectric effects are present, the entropic behavior of such systems changes somewhat. An optimum power extraction temperature is found to be related to the so-called CNCA optimum temperature. The opportunity to generate thermoelectric power in a temperature gap is,discussed in some detail in a fashion that renders it analogous to many current thermodynamic optimization studies.