High temperature solar thermoelectric generator – Indoor characterization method and modeling

•Experimental study of Solar Thermoelectric Generator working at high temperature.•Characterization of Si80Ge20 thermoelectric material coupled with TiAlN absorber.•Development of a predictive physical model for much higher temperatures.•Modeling of electric power generated by a thermoelectric cascaded device.

This paper presents an experimental study of a STEG (solar thermoelectric generator) working at high concentration ratio (>100) and high temperature (≥450 °C). An indoor characterization set-up based on Si80Ge20 thermoelectric material coupled with a selective absorber and a solar concentrating simulator was developed. The goal was to validate a physical model allowing to predict performances of such thermoelectric material for much higher temperatures. Predictive efficiencies were thus extrapolated for a working temperature beyond 800 °C. The critical issue deals with the best system dimensioning taking into account the concentrator size, and the efficiency versus the TEG (thermoelectric generator) size.