TY - JOUR

T1 - Review

T2 - Ultraviolet Fluorescence as Assessment Tool for Photovoltaic Modules

AU - Köntges, Marc

AU - Morlier, Arnaud

AU - Eder, Gabriele

AU - Fleis, Eckhard

AU - Kubicek, Bernhard

AU - Lin, Jay

N1 - Funding information: Manuscript received November 18, 2019; revised December 14, 2019; accepted December 19, 2019. Date of publication January 14, 2020; date of current version February 19, 2020. This work was supported in part by the German Federal Ministry for Economic Affairs and Energy under Grant 0325735D and Grant 0324304C, and in part by the Austrian Klima-& Energiefonds under the project “AMSEL,” FFGnr.:848771. (Corresponding author: Marc Köntges.) M. Köntges and A. Morlier are with the Institute for Solar Energy Reasearch Hamelin, 31860 Emmerthal, Germany (e-mail: m.koentges@isfh.de; a.morlier@isfh.de).

PY - 2020/2/19

Y1 - 2020/2/19

N2 - 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.

AB - 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.

KW - fault diagnosis

KW - power system reliability

KW - solar panels

KW - Ultraviolet fluorescence

UR - http://www.scopus.com/inward/record.url?scp=85080913516&partnerID=8YFLogxK

U2 - 10.1109/JPHOTOV.2019.2961781

DO - 10.1109/JPHOTOV.2019.2961781

M3 - Review article

AN - SCOPUS:85080913516

VL - 10

SP - 616

EP - 633

JO - IEEE journal of photovoltaics

JF - IEEE journal of photovoltaics

SN - 2156-3381

IS - 2

M1 - 8959389

ER -