Performance Validation of an Irradiance Redistribution Guide

Science Applications International Corporation has used a unique nonimaging-optical global optimization computer code, NICOS, to design an innovative secondary concentrator for the National Renewable Energy Laboratory (NREL). NICOS allows for the optimal design of such devices to achieve a variety of irradiance distributions on a desired target. The case of interest to NREL called for a uniformirradiance of concentrated sunlight over a relatively large area and at a reasonable Solar Furnace (HFSF) was reshaped from a near-Gaussian distribution to a nearly uniform one, the designs generated have been called irradiance redistribution guides (IRG). A design featuring reentrant optics was selected for fabrication and testing. This IRG has been fabricated and tested at the HFSF to comparepredicted and measured performance. The IRG's performance is close to the theoretical predictions. Much of the performance difference can be explained by discrepancies between the actual HFSF performance relative to that assumed in the NICOS predictions. This IRG will be useful for applications in which uniform solar concentration; at moderate flux is required. In general, the design methodologyand resulting devices can provide a new way to satisfy diverse flux tailoring needs.