Experimental optimization of operating conditions for concentrating photovoltaic-thermoelectric hybrid system

This paper provides a comprehensive experimental optimization process of the concentrating photovoltaic-thermoelectric hybrid system, considering the total input energy, the output characteristics of coupling devices, the system structure and the electrical connection modes. An experimental system with an adjustable light source is established. The concentrating photovoltaic-thermoelectric hybrid system is firstly compared with the concentrating photovoltaic system at varying optical concentration ratios to verify the feasibility of hybrid utilization and to illustrate the effect of optical concentration ratio on the hybrid performance. Then, the effects of the photovoltaic output voltage and the thermoelectric load resistance on the temperature and output power of the hybrid system are investigated to obtain the optimum output characteristics. Subsequently, the influence of the thermoelectric thermal resistance determined by its number and structure on the hybrid performance is studied. Finally, two electrical connection modes (series and parallel) of the thermoelectric modules are compared considering the same thermoelectric thermal resistance. The results demonstrate the superiority of the concentrating photovoltaic-thermoelectric hybrid system and the importance of optimizing the operating conditions. The obtained results can provide some useful guidance for the design and operation optimization of the practical concentrating photovoltaic-thermoelectric hybrid system.