CNRS-PROMES published an article about SFERA-III in the Optics Express, a renowned open-access journal specialised in peer-reviewed articles that emphasize scientific and technology innovations in all aspects of optics and photonics.
The paper, entitled “Computation of canting errors in heliostats by flux map fitting: experimental assessment”, was published on 21 December 2020 and is available in open access.
In solar tower plants, thousands of heliostats reflect sunlight into a central receiver. Heliostats consist of a subset of mirrors called facets that must be perfectly oriented (i.e., canted) to concentrate as much solar radiation as possible. This study presents and validates the so-called flux map fitting technique to detect and correct canting errors. The computed distributions were matched to a series of images through an optimization algorithm. According to the sensitivity analysis, three images spread along a single day provide sufficient information for the algorithm to succeed. Using this methodology, four heliostats at the THEMIS research facility were recanted, thereby substantially increasing the optical quality in three of them. The procedure to infer the heliostat aimpoint was assessed.
Authors Alberto Sánchez-González, Benjamin Grange, and Cyril Caliot
Cite as Alberto Sánchez-González, Benjamin Grange, and Cyril Caliot, “Computation of canting errors in heliostats by flux map fitting: experimental assessment,” Opt. Express 28, 39868-39889 (2020); https://doi.org/10.1364/OE.412116
This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 823802