Optical design of centered-receiver trough-based CPV system

Concentrating photovoltaic (CPV) systems require less area of the solar cell while achieving a high efficiency. One of the development factors in the CPV includes the irradiance uniformity over the solar cell. To overcome this issue, a parabolic trough-based optical design is proposed using two nonimaging secondary reflectors: reflective grooves and compound parabolic concentrator (CPC). The reflective grooves convert the line focus to a square shape irradiance distribution, and the CPC is used for redirecting the rays to the receiver. The proposed system delivers the concentrated light over the solar cell having a size of 30 × 30 mm2 at the center of the trough. The CPV system reduces the number of cells compared with conventional trough-based CPV systems by attaining the concentration ratio of 285. The results indicate that the system has achieved an optical efficiency of 60% at an acceptance angle of ±2 deg. The detailed optical design and raytracing simulation are presented showing that the proposed concentrator can achieve significantly higher overall concentration while maintaining irradiance uniformity.