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

Abstract

Concentrator photovoltaics (CPVs) can efficiently convert light into electricity. However, conventional CPVs require large and heavy tracking systems. Microtracking CPVs (MTCPVs) can be used to address this problem. Most MTCPV systems have a limited angle of incidence (AOI) and do not use diffuse light. Therefore, in this study, a spherical lens-based MTCPV (SMTCPV) with a pin-type secondary optical element (SOE) was developed. The overlap between spherical lenses was adjusted. Pin-type SOEs are inserted between the spherical lenses, thereby increasing the acceptable AOI. Optical analysis and calculations of the interaction between the overlapping spherical lenses and pin-type SOEs were performed. As a result, the optical efficiency of 59% was maintained at all angles when the gap was considered. Further, the maximum AOI was 64.7° in the direction of adjacent spherical lenses and 90° in the gap direction.