Abstract
Since 2010, the ultraviolet fluorescence (UVF) method is used to identify defects in wafer-based crystalline silicon photovoltaic (PV) modules. We summarize all known applications of fluorescence imaging methods on PV modules to identify defects and characteristics. The aim of this review is to present the basic principles for the interpretation of UVF images. The method allows for detection of cell cracks in a chronological order of occurrence, visualizing hot parts in a PV module, and identifying deviating bill of materials of PV modules. The effects of various material combinations on the UVF are reproduced in the lab and explained for the first time. Seasonal effects on the UVF are presented for the first time. In addition, some not yet understood features in the images are shown and discussed. Furthermore, the application of UVF imaging for manual, hood-based, and drone-based inspection is presented. The analysis speed of the three methods has been measured under real conditions. For the manual inspection, we found an evaluation speed of 250 modules/h, for a hood-based system 200 modules/h and the drone-based method allows an imaging speed of up to 720 modules/h.
Highlights
U LTRAVIOLET fluorescence (UVF) measurements are widely used for many applications
In 2010, Schlothauer proved that dark lines in the UVF images of PV modules correlate with cracks in the solar cells [7], [8]
We introduce the basics of the UVF method as it is used for PV module inspection
Summary
U LTRAVIOLET fluorescence (UVF) measurements are widely used for many applications. In 2010, Schlothauer proved that dark lines in the UVF images of PV modules correlate with cracks in the solar cells [7], [8]. One of the authors demonstrated the application of the method in a PV system to analyze the fraction of cell cracks in PV modules [9]. Multiple publications followed describing the development of mobile measurements systems, enabling PV applications of UVF imaging and spectroscopy both in the field and the laboratory [10], [11], [12], [13], [14]. We give a detailed look on the applicability of the method for PV module reliability analysis and on the practicability of the method
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
