ANALYSIS OF TEXTURED SOLAR-CELLS AT VARIOUS ANGLES OF INCIDENCE - FRESNEL CONCENTRATION TO 500 SUNS

Textured solar cells are becoming the norm in terrestrial applications . In most applications of textured solar cells the light will be incid ent at various angles, i.e., time of day for flat plate collectors or radial position for a concentrating lens system. However, a detailed a nalysis of the performance of light trapping geometries at various ang les of incidence has not been reported. A quantitative analysis of the light trapping of several texturing geometries as a function of angle of incidence, in the context of a concentrating Fresnel lens, is pres ented for the first time. For normally incident light at one sun inten sity the improvement in collection efficiency for the textured cells c ompared to a planar cell is 4.84%, 7.74%, and 12.72% for the slats, in verted pyramids, and perpendicular slats geometries, respectively. At 500 suns concentration under a Fresnel lens the collection efficiency compared to the planar cell is 5.26%, 10.9%, and 12.28% for the same t hree texturing geometries. This implies that a linear response to conc entration does not apply for textured surfaces. Collection efficiency as a function of angle of incidence is also used to provide guidelines for cell orientation within flat plate arrays to provide maximum coll ection efficiency at several hours of the day.