The effect of porous media on a solar thermoelectric energy harvesting system

Abstract

This present study investigates the effect of adding a porous medium to the hot surface of a system for thermoelectric power generation (TEG). The thermal efficiency, electromotive force (e.m.f) and output power for TEGs with and without porous media are compared. Four TEG modules were connected in series and connected to an electrical data logger. The hot side of the TEG was covered by a parabolic dome and along the hot surface of the TEG there were placed various porous media: fine sand, coarse sand, and crush stone. The cooling side of the TEG modules was set on a heatsink and floating in water. The results of the maximum temperature difference between the two sides of the TEGs increased by 30.23% for fine sand, and 34.88% for crush stone compared to the temperature difference without porous media. The porous medium of crush stone shows the maximum temperature difference of 5.8 °C and the e.m.f of the system is increased to a maximum of 209 mV or increases about 16.11% over that without porous media.