Kaleidoscope homogenizers sensitivity to shading

Dense-array CPV collectors require a homogenous flux distribution on the PV module in order to maximize efficiency. The kaleidoscope homogenizer concept is considered to be the solution for this requirement, and has shown good homogenization ability in previous analyses. These analyses, however, did not include varying shading situations created throughout the daily operation of a field of collectors, especially in dense fields. We show that such conditions reduce the kaleidoscope ability to homogenize to varying amounts, depending on field density, and that this has implications on the selection of suitable homogenizer length for a CPV field. The vertical-junction concept is seen as a possible solution.

► Flux heterogeneity varies with all geometry variables.
► Location of heterogeneity minima also varies with geometry.
► For sparse fields, short homogenizers (n = 1.1) suffice).
► Denser fields benefit from longer homogenizer.
► There is value in non-series solutions to PV-module design.