Record high solar concentration ratio for photovoltaics: Experimental validation for achieving effective concentration of >1200 suns

The optical ultra-high concentration ratio levels are still not demonstrated enough due to the high complexity of the associated optical designs offering restricted angular freedom, and the expansive cost that might be required for such a breakthrough. This research proposes a novel optical design of an ultra-high concentrating photovoltaic system that can achieve a geometric concentration of 5831×. The system consists of four flat silicon-on-glass (SOG) Fresnel lenses as primary optics, four reflectors as secondary optics, and four-domed tertiary optical elements (TOE) that will refract the sunlight onto a 5.5×5.5mm² triple-junction solar cell. A complete proof-of-concept module has been developed, assembled, and tested. The experiments were conducted based on instantaneous and one hour of continuous measurement. The obtained results showed that the system can achieve a higher effective concentration ratio of 1291 suns when deploying ReflecTech polymer compared to aluminium reflective film of 984 suns and Pilkington Optimirror of 1220 suns. The developed and tested compact ultra-high concentrator photovoltaic system yielded the highest geometrical concentration ratio and the highest effective concentration ratio achieved experimentally.