Hybrid photovoltaic-thermoelectric system using a novel spectral splitting solar concentrator

Abstract

A hybrid photovoltaic-thermoelectric (PV-TE) system employing a novel solar concentrator is designed and constructed to demonstrate the feasibility of improving the overall efficiency of light-to-electricity conversion based on spectral splitting strategy. The concentrator consists of four rectangular dichroic mirrors arranged in a crossed V-trough configuration that reflects and concentrates the visible spectrum onto a photovoltaic cell in the centre while passes the infrared spectrum onto a thermal absorber to produce heat for a thermoelectric generator. The experimental results show that the overall efficiency of the hybrid PV-TE system is 16.9% compared to 15.9% of the same configuration except for using specular aluminium mirrors. An increase in the overall efficiency by 6.3% was achieved due to thermoelectric harvesting of the light energy in infrared spectrum. The results also show that a significant increase in the power output from 12.41 mW in the bare cell to 62.04 mW of the same cell in the concentrated system, indicating the advantages of using concentration system, particularly beneficial to high-cost solar cells, such as GaAs and GaInP.