A conical beam concentrator consisting of a series of six component lenses which receive a convergent conical beam of diffused sunlight and emit a concentrated circular whole beam. There are six annular lenses aligned on the veritcal optic axis, as follows; an upper lens with a convex conical section which forms the apex of the concentrator, and five lower lenses with inset convex conical sections of graduated increased diameters. Each lens consists of twelve sections separated by radial walls which are covered by an opaque coating of paint which intercepts radiation not perpendicular to the convex conical sections of the lenses. The upper and lower conical walls of each lens are also covered by an opaque layer of paint to intercept extraneous radiation.