Calculation of the interaction between an overlapping spherical lens and a pin-type second optical element for spherical lens microtracking concentrator photovoltaic with a wide angle of incidence

Concentrator photovoltaics (CPV) can efficiently convert light into electricity; however, conventional CPVs require large and heavy tracking systems. Microtracking CPVs (MTCPVs) can solve this significant problem. Most MTCPV systems have a limited angle of incidence (AOI). If diffuse light was used, MTCPV required traveling light from top to bottom. In this study, a spherical-lens-based microtracking CPV (SMTCPV) with a pin-type second optical element (SOE) was developed. In SMTCPV, the light travel light from above to below. Pin-type SOEs were inserted between the spherical lenses, thus increasing the acceptable wide AOI. Optical analysis and calculations of the interaction between overlapping spherical lenses and pin-type SOEs were performed. An optical efficiency of 59% was maintained at any angle when the gap was considered. The maximum AOI was 64.7 degrees in the direction of adjacent spherical lenses and 90 degrees in the gap direction.