Optimal Pellet Geometries for Thermoelectric Power Generation

The geometry of the semiconductor pellets (i.e., the number of them and their height) within thermoelectric modules (TEMs) operating in generation mode is optimized in order to maximize either their performance (i.e., output power) or their conversion efficiency for a specified performance. This is accomplished for a specified resistive load on a TEM as a function of its effective footprint, i.e., sum of the cross-sectional areas of its pellets. The load resistances which maximize performance or efficiency when pellet geometry is specified are also provided. The analyses are performed in the absence and then presence of electrical contact resistance at the interconnects between pellets. They apply for a prescribed temperature difference across a TEM that is small enough for the properties of its pellets to be considered constant. Examples illustrate the application and implications of the results.