A new concept for a fixed-mirror solar concentrator is described. The fixed, stepped surface of the proposed cylindrical mirror is designed to produce a sharply focused line image regardless of the incident sun direction. This is in contrast with the severe off-axis aberration (hence, poor concentration factor) of a parabolic mirror for all sun directions other than on-axis. It is shown that 1) the heat absorber follows a circular path to remain in the focus as the sun moves, 2) the annual light losses from self-shadowing of the "stepped structure of the mirror surface can amount to less than %in for appropriate mirror orientation, 3) by facing the mirror in a southerly direction in the northern hemisphere) , the winter deficit in sun input can be significantly compensated, and 4) practical concentration factors of around 50 can be achieved with a single stage of concentration, 80 with a second stage of concentration.

Date Published: 15 February 1977
PDF: 7 pages
Proc. SPIE 0085, Solar Energy Utilization II, (15 February 1977); doi: 10.1117/12.954950

Published in SPIE Proceedings Vol. 0085:
Solar Energy Utilization II