The application of a kaleidoscope as a flux homogenizer to a concentrating photovoltaics system with a central receiver is investigated. The optical setup of a primary dish-type concentrator, a secondary homogenizer optics, and a photovoltaic receiver is simulated using ray tracing. The influence of various deviations from the ideal—namely sunshape (circumsolar radiation), shading, tracking error, and shape of the primary optical concentrator—on the performance of the homogenizer is analyzed quantitatively using the optical efficiency and the normalized standard deviation as a measure of inhomogeneity. Flux distributions for different progressively increasing deviations are discussed qualitatively. Experimental validation of the simulation is presented. It is demonstrated that the performance of the homogenizer is not particularly sensitive to sunshape. If sufficient length is provided, the homogenizer effectively compensates for tracking error, misalignment, and shape deviations of the primary concentrator. Yet despite the presence of the homogenizer, shading due to the holder of the receiver significantly affects the flux distribution at the receiver.
© 2013 Optical Society of America
Optical Design and Fabrication
Original Manuscript: January 23, 2013
Revised Manuscript: March 27, 2013
Manuscript Accepted: March 28, 2013
Published: April 24, 2013
Henning Helmers, Wei Yi Thor, Thomas Schmidt, De Wet van Rooyen, and Andreas W. Bett, "Optical analysis of deviations in a concentrating photovoltaics central receiver system with a flux homogenizer," Appl. Opt. 52, 2974-2984 (2013)