Enhancing the performance of the solar thermoelectric generator in unconcentrated and concentrated light

Abstract

The solar thermoelectric generator is undoubtedly an important candidate to convert solar into electric energy. The current efficiency of the thermoelectric generator is low, but recent research indicates an improvement in efficiency. The paper presents a method that leads to performance enhancement of the solar thermoelectric generator. An absorbent layer comprising of metallic oxides and additives was deposited by the spray deposition technique on the hot side of the solar thermoelectric generator to increase irradiance absorption. The main properties of the absorbent layer consist of an optimized IR absorption, good thermal transmission to the contact material, and thermal resistance. The absorbent layer deposited on the hot side of the STEG has low thermal emittance 0.073, high absorbance 0.98 and high stability, which makes it a very good candidate for use as an absorbent layer for improving the performance of the STEG. The new solar thermoelectric generator is studied in two environmental situations: artificial light in the lab, from 600 W/m2 to 1200 W/m2 and in concentrated light from 20 suns to 80 suns. Analysis of the results obtained shows an increase in power generation more than 25 % for the irradiance around 1 sun and up to 82 % for the concentration light.