Luminescent Solar Concentrator with a Fibre Geometry
Summary
The potential of a luminescent solar concentrator (LSC) with a fibre geometry to concentrate the sunlight has been explored, by means of a theoretical comparison with the conventional at plate LSC and by simulating the optical efficiency with the ray tracing programme PVtrace. In addition clear sky diffuse and direct spectra have been modelled for London and their contribution to the photons collected have been compared. It is found that looking at the losses caused by reflection, host absorption and the escape cone in combination with the geometrical concentration G, the fibre is found to be 1.5 times as efficient as the flat plate LSC when 0.1 m-1 host absorption, low doping and normal incident light is assumed. The simulation showed that, as the path length for absorbed photons to the edge is long, maximum re-absorption occurs, in fibres of 10 cm length and 1 mm radius. Increasing the length from that point, hardly affects the optical efficiency, while the geometrical concentration increases, resulting in a high concentrating potential. A coated fibre is found to be more efficient than a homogeneous doped fibre, because the trapping efficiency is higher when photons are emitted close to the surface in of a cylindrical LSC.