Advanced UV-fluorescence image analysis for early detection of PV-power degradation

Karl A. Berger, Lukas Neumaier, Gabriele Eder, Yuliya Voronko, Gusztav Ujvari, Karl Knöbl

Publikation: Beitrag in FachzeitschriftArtikelBegutachtung

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Reliability and durability of photovoltaic modules are a key factor for the development of emerging
PV markets worldwide. Reliability is directly dependent on the chemical and physical stability of the polymeric
encapsulation materials. One method capable of detecting ageing effects of the polymeric encapsulant directly
on-site is UltraViolet Fluorescence (UVF) imaging. This work deals with advanced imaging analysis of UVF
images and the subsequent correlation to electrical parameters of PV modules, which were exposed to climatespecific,
long-term, accelerated aging procedures. For establishing a correlation, a so called UVF area ratio was
established, resulting from the typical fluorescence patterns of the encapsulant material, which arise due to stress
impact (e.g., water vapor ingress, elevated temperature, irradiation) and aging/degradation processes. Results
of the data analysis show a clear correlation of the UVF area ratios and the electrical parameters with increasing
aging time. In particular, the relationship between power and series resistance could be confirmed by extensive
long-term test series with different climate-specific aging processes. Assuming the same type of polymeric
encapsulation and backsheet and a comparable climate, determining the UVF area ratio can be used to estimate
the service life and electrical power dissipation of each module installed in a PV array.
Seiten (von - bis)1-10
FachzeitschriftEPJ Photovoltaics
PublikationsstatusVeröffentlicht - 10 Feb. 2023

Research Field

  • Energy Conversion and Hydrogen Technologies


  • photovoltaics
  • reliability
  • imaging
  • operation
  • maintenance
  • non-invasive diagnostic

Web of Science subject categories (JCR Impact Factors)

  • Physics, Applied

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