Experimental and numerical study on the transient behavior of multi-junction solar cell-thermoelectric generator hybrid system

An experimental investigation and numerical verification of the transient behavior of a hybrid concentrating triple junction solar cell-thermoelectric generator system is presented in this paper. The experimental work is accomplished under varying concentrated solar radiations using a solar simulator, and the numerical study is conducted using COMSOL Multiphysics Modeling Software. An arbitrary pattern for the solar radiation varying between 0 and 39 suns is considered in the experiments and numerical simulation. Time-dependent temperatures of the concentrating triple-junction solar cell and hot and cold sides of the thermoelectric generator along with short circuit current, open circuit voltage and maximum powers are obtained experimentally. The results indicate that the output power by the concentrating triple-junction solar cell is fluctuating very fast with changing the solar radiation. Due to the thermal capacity and thermal resistance of the thermoelectric generator, this variation for the temperatures and output power of the thermoelectric generator is more gradually. The results also indicate that using thermoelectric generator in the hybrid system leads to having more stable overall output power. Furthermore, the contribution of the thermoelectric generator in the overall power generation by the system can be enhanced with material and geometrical optimization.