Abstract
The solar thermoelectric generator (STEG) is regarded as a promising energy conversion technology to convert solar heat into electricity. Considering the real solar irradiance, impedance matching, and interface contacts, a comprehensive three-dimensional transient thermal-electric numerical model for the STEG is established to evaluate its dynamic response and energy recovery potential. The transient performance prediction of the STEG during the whole daytime is completed for the first time. Due to the temperature limitation of thermoelectric materials, the allowable concentration ratio for the Bi2Te3-based STEG is 150 suns, corresponding to the average daytime output power of 13.16 W and the average daytime conversion efficiency of 6.15%. Dynamic responses of output voltage and conversion efficiency present the same changing trend as solar irradiance. However, the steady-state numerical model underestimates the output power by 6.91% and overestimates the conversion efficiency by 1.85%, due to the ignorance of thermal inertia during thermal diffusion. The established transient model can predict more reasonable results and is well verified via transient experiments. It is obtained that the STEG can produce 491.4 kJ of electricity a day and 49.79 kW h a year, and the theoretical cost-recovery cycle for the cost of the thermoelectric generator module is 1.61 years.
•A three-dimensional transient thermal-electric model of the STEG is established.•The transient performance prediction of the STEG during the whole daytime is completed.•The steady-state model underestimates output power and overestimates efficiency.•The STEG can produce 491.4 kJ of electricity a day and 49.79 kW h a year.•Analysis for the energy recovery potential of the STEG is performed.