Increase in the efficiency of electricity production with a thermoelectric generator (TEG)

Abstract

Currently used TEG modules have low efficiency of about 5%. The energy generated by the TEG module depends on the temperature difference between the module surfaces. Heat exchange between the heat source and the module surface takes place through the contact between two rough solid surfaces. This creates contact resistance. It can be reduced by using a substance filling the empty spaces between the contact surfaces and applying pressure. During the tests, the efficiency of electricity generation with a thermoelectric generator was measured (TEG) at various pressure forces. The tests were carried out at a pressure force of 250 N, 500 N, 750 N and 1000 N. The selected values of pressure do not exceed the limit value arising from the thermoelectric generator (TEG) design. A copper element constituting the heat source was heated in a furnace. Next, it was pressed at an adequate force to the generator, which was placed on a water cooler. The impact of conductive materials placed between the faces of the heat source and the TEG on the generation of electricity was examined. At low forces, the use of a thermal pad as an intermediary substance does not result in improved heat transfer in the heat source—TEG generator system. Better filling of voids is provided by thermally conductive paste due to its properties.