title: Faceted concentrators optimized for homogeneous radiation.
abstract: For technical reasons, large three-dimensional compound parabolic concentrators (CPC's) are often built from facets with either no or only one-dimensional curvature. We analyze CPC approximations made with various numbers of axial and circumferential subdivisions. Incident radiation within half-angles of 10 degrees and 30 degrees is considered. The reflectivity of the mirrors is assumed to be 90% or 95%. The performance of faceted concentrators can be significantly improved by optimization as compared with heuristic CPC approaches. The highest increase in transmission that we observed was 19% greater as compared with that of a heuristic CPC approximation. The shapes of the optimized concentrators differ from that of a classic CPC, and most of the optimized concentrators are longer than a classic CPC. For practical concentrators with a small number of facets, the optimized geometry provides better performance than a heuristic approximation of the CPC shape.
authors.affiliation: Optics & Energy Consulting, Stoeberlstrasse 68, D-80686 Munich, Germany. timinger@oec.net
authors.forename: A
authors.initials: A
authors.lastname: Timinger
authors.forename: A
authors.initials: A
authors.lastname: Kribus
authors.forename: P
authors.initials: P
authors.lastname: Doron
authors.forename: H
authors.initials: H
authors.lastname: Ries