TECHNOLOGY FOCUS - POLYMERS - Preferred Method: A second plastic layer made of a second granulate formulation on the upper side of the first plastic layer prior to structuring using a second extruder, is applied by coextrusion. A third plastic layer made from the second or a third extruder, is applied by means of coextrusion on the lower side of the first plastic layer, prior to structuring. The surface of the concentrator is coated with a scratch-resistant, an anti-dust coating and/or anti-reflective coating before the structuring. Preferred Components: The second and/or optionally third plastic layer is a multi-layered coextrudate. The second and/or optionally third plastic layer or at least a partial layer of the second and optionally third plastic layer is provided with the UV stabilizer and UV absorber. At least one UV absorber is at least a benzotriazole and at least one triazine and the UV stabilizer is at least one hindered piperidine compound. The refractive index of the topmost layer with an accuracy of 5% forms the square root of the refractive index of the underlying layer. The first plastic layer is a transparent material, e.g. styrene acrylonitrile, polycarbonate, polyurethane, polycycloolefin, polystyrene, styrene copolymer, polyester, preferably polyethylene terephthalate or polyethylene terephthalate glycol, poly(meth)acrylate, or a mixture of the polymers. The second and optionally third plastic layer is a layer of poly(meth)acrylate and/or fluropolymer, preferably a mixture of poly(methyl methacrylate) and poly(vinylene fluoride) or a multilayered system of poly(methyl methacrylate) and poly(vinylene fluoride). The concentrator comprises a surface finishing with dirt-repellent, ant reflective and scratch resistance-improving properties, the UV stabilizer and UV absorber containing second plastic layer with a thickness, the first plastic layer, and a third plastic layer with a thickness of 5-500 mu m, preferably 10-250 mu m. The individual Fresnel lens is an angular, radial or linear structure. The Fresnel lens is arranged in grid- or line shape or irregularly to each other. EXAMPLE - No suitable example given.