In order to optimize the performance of a thermoelectric device, an attempt is made to clarify the dependence on the temperature of its cold side and the size of the incisions made on its lateral faces. By means of experimental measurements and numerical simulations, the temperature difference between the hot and cold sides of the device is estimated, and the primary measures of performance, namely the electric power and the conversion efficiency, are examined for variations in the size of the incisions and in the cold-side temperature. The results of the simulations are in fairly good agreement with the experimental ones. Furthermore, the relationship between electrical power, conversion efficiency, and incision size were found to depend on the cold-side temperature. (c) 2004 Published by Elsevier Ltd.