Degradation of Monocrystalline Silicon Photovoltaic Modules from a 10-Year-Old Rooftop System in Florida

Dylan J. Colvin, Nafis Iqbal, Julian H. Yerger, Fang Li, Archana Sinha, Galya Vicnansky, Gabriele Brummer, Nancy Zheng, Eric J. Schneller, James Barkaszi, Govindasamy Tamizhmani, Kristopher O. Davis

Research output: Contribution to journalArticlepeer-review

5 Scopus citations


A system of 180 monocrystalline aluminum back-surface field modules were installed in Cocoa, Florida, for 10 years. In total, 156 modules are characterized and compared to 3 controls. Power degradation rates vary between-0.14% to-3.22% per year, with median and average rates of-0.92% and-1.05% per year, respectively. The losses are primarily resistive with minor optical and recombination loss contributions. Electroluminescence imaging shows a characteristic pattern, which is shown to be resistive in nature when compared to photoluminescence. Resistive losses are due to corrosion of the rear contact Ag/solder interface and, to a much lesser degree, gridline Ag oxidation. Moisture ingress through the backsheet is likely responsible for mediating corrosion. Optical losses are due mostly to a combination of antireflection coating degradation, minor encapsulant browning, and delamination. Minor front contact corrosion may contribute to recombination. This study expands upon previous work on this vintage of the module by examining a large sample set, comprehensive characterization including techniques not previously used on these modules, and a comparison between two other systems of different climates.

Original languageEnglish (US)
Pages (from-to)275-282
Number of pages8
JournalIEEE Journal of Photovoltaics
Issue number2
StatePublished - Mar 1 2023


  • Aluminum back-surface field (Al-BSF)
  • degradation
  • electroluminescence imaging
  • field study
  • rear contact

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering


Dive into the research topics of 'Degradation of Monocrystalline Silicon Photovoltaic Modules from a 10-Year-Old Rooftop System in Florida'. Together they form a unique fingerprint.

Cite this