Patent ID: 7667833

Claim:
A method to aligning a parabolic trough solar concentrator, comprising: (a) providing a line-focusing parabolic trough concentrator module, comprising at least two rows and at least one column of mirror facets, and a linear receiver; (b) providing an alignment fixture comprising at least one off-axis camera position for each row of the module; (c) positioning the alignment fixture perpendicularly to trough of the module; (d) determining the boresight offset of the center of the alignment fixture and thereby the locations of the off-axis camera positions; (e) photographing the image of the receiver in a mirror facet with a camera at the off-axis camera position for that row of mirror facets; (f) calculating a theoretical projected image of the concentrator and the receiver image in the mirror facet as seen by the camera at the off-axis camera position using geometric ray tracing; (g) shifting the theoretical projected image to account for the boresight offset and overlaying the theoretical projected image on the photographic image; and (h) adjusting the mirror facet to bring the photographic image to coincide with the theoretical projected image in the overlay.