Geometric characterisation of a parabolic trough solar power plant with flexible film mirrors using 3D laser scanning

This paper presents the methodology for geometric characterisation using 3D laser scanning technology applied to parabolic trough concentrators (PTCs) of a solar thermal power plant that utilises flexible polymeric film mirror technology with a 7.0 m aperture. Firstly, the concentrator profiles were compared to the theoretical parabolic profile to identify geometric deviations. Results revealed deformations in the parabolic profile associated with the loss of structural stability of the metal sheets that support the flexible film mirrors, as well as permanent dents caused by wind exposure. Secondly, two point clouds of the solar field, collected 18 months apart, were superimposed to detect geometric changes over time. The analysis showed that the northern ends of some concentrators underwent alterations, likely due to predominant frontal winds. The main contributions of this work include: the application of 3D laser scanning technology for geometric assessment across the entire solar field; the evaluation of the structural behaviour of flexible film mirror PTCs after 18 months of operation; and the use of advanced point cloud comparison techniques performed directly in a 3D computational environment. The presented methodology demonstrated potential for applications in the characterisation and geometric monitoring of solar thermal power plants, contributing to improvements in operational efficiency.