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Title: Evaluation of moisture ingress from the perimeter of photovoltaic modules: Evaluation of moisture ingress

Abstract

Many thin film photovoltaic (PV) technologies can be sensitive to corrosion induced by the presence of water vapor in the packaging materials. Typically impermeable front and backsheets are used in conjunction with an edge-seal around the perimeter to prevent water vapor ingress. These edge-seal materials are often made of a polyisobutylene resin filled with desiccant, which dramatically increases the time for moisture to reach sensitive module components. While edge-seals can prevent moisture ingress, even the lowest diffusivity transparent encapsulant materials are insufficient for the lifetime of a module. To evaluate the performance of edge-seal and encapsulant materials in a manner that simulates their function in a PV module, an optical method was devised where ingress is detected by reaction of a Ca film with water. Using this method, we have exposed test samples to heat and humidity allowing quantitative comparison of different edge-seal and encapsulant materials. Next, we use measurements of polymer diffusivity and solubility to evaluate the ability to model this moisture ingress. Here, we find good agreement between these two methods highlighting the much greater ability of polyisobutylene materials to keep moisture out as compared with typical encapsulant materials used in the PV industry.

Authors:
 [1];  [1];  [1]
  1. National Renewable Energy Laboratory (NREL), Golden CO 80401 USA
Publication Date:
Research Org.:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S)
OSTI Identifier:
1405904
Report Number(s):
NREL/JA-5J00-57218
Journal ID: ISSN 1062-7995
DOE Contract Number:  
AC36-08GO28308
Resource Type:
Journal Article
Journal Name:
Progress in Photovoltaics
Additional Journal Information:
Journal Volume: 22; Journal Issue: 11; Journal ID: ISSN 1062-7995
Publisher:
Wiley
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; 36 MATERIALS SCIENCE; photovoltaic; edge-seal; moisture; humidity; polyisobutylene; desiccant; encapsulant

Citation Formats

Kempe, Michael D., Dameron, Arrelaine A., and Reese, Matthew O. Evaluation of moisture ingress from the perimeter of photovoltaic modules: Evaluation of moisture ingress. United States: N. p., 2013. Web. doi:10.1002/pip.2374.
Kempe, Michael D., Dameron, Arrelaine A., & Reese, Matthew O. Evaluation of moisture ingress from the perimeter of photovoltaic modules: Evaluation of moisture ingress. United States. doi:10.1002/pip.2374.
Kempe, Michael D., Dameron, Arrelaine A., and Reese, Matthew O. Tue . "Evaluation of moisture ingress from the perimeter of photovoltaic modules: Evaluation of moisture ingress". United States. doi:10.1002/pip.2374.
@article{osti_1405904,
title = {Evaluation of moisture ingress from the perimeter of photovoltaic modules: Evaluation of moisture ingress},
author = {Kempe, Michael D. and Dameron, Arrelaine A. and Reese, Matthew O.},
abstractNote = {Many thin film photovoltaic (PV) technologies can be sensitive to corrosion induced by the presence of water vapor in the packaging materials. Typically impermeable front and backsheets are used in conjunction with an edge-seal around the perimeter to prevent water vapor ingress. These edge-seal materials are often made of a polyisobutylene resin filled with desiccant, which dramatically increases the time for moisture to reach sensitive module components. While edge-seals can prevent moisture ingress, even the lowest diffusivity transparent encapsulant materials are insufficient for the lifetime of a module. To evaluate the performance of edge-seal and encapsulant materials in a manner that simulates their function in a PV module, an optical method was devised where ingress is detected by reaction of a Ca film with water. Using this method, we have exposed test samples to heat and humidity allowing quantitative comparison of different edge-seal and encapsulant materials. Next, we use measurements of polymer diffusivity and solubility to evaluate the ability to model this moisture ingress. Here, we find good agreement between these two methods highlighting the much greater ability of polyisobutylene materials to keep moisture out as compared with typical encapsulant materials used in the PV industry.},
doi = {10.1002/pip.2374},
journal = {Progress in Photovoltaics},
issn = {1062-7995},
number = 11,
volume = 22,
place = {United States},
year = {2013},
month = {5}
}

Works referenced in this record:

Effect of immobilizing adsorption on the diffusion time lag
journal, October 1969


Durable polyisobutylene edge sealants for organic electronics and electrochemical devices
journal, May 2012


Diffusion and solubility of methane in polyisobutylene
journal, May 1969

  • Lundberg, J. L.; Mooney, E. J.; Rogers, C. E.
  • Journal of Polymer Science Part A-2: Polymer Physics, Vol. 7, Issue 5
  • DOI: 10.1002/pol.1969.160070517

Transport phenomena through polymeric systems
journal, August 2001


The low-temperature oxidation of calcium by water vapor
journal, October 1977


Modeling of rates of moisture ingress into photovoltaic modules
journal, October 2006


The effect of damp-heat and UV aging tests on the optical properties of silicone and EVA encapsulants
journal, August 2010

  • McIntosh, Keith R.; Powell, Nick E.; Norris, Ann W.
  • Progress in Photovoltaics: Research and Applications, Vol. 19, Issue 3
  • DOI: 10.1002/pip.1025

A study of the influence of the Ga content on the long-term stability of Cu(In,Ga)Se2 thin film solar cells
journal, May 2003


Factors Affecting the Stability of CdTe/CdS Solar Cells Deduced from Stress Tests at Elevated Temperature
journal, April 2003

  • Visoly-Fisher, I.; Dobson, K. D.; Nair, J.
  • Advanced Functional Materials, Vol. 13, Issue 4
  • DOI: 10.1002/adfm.200304259

Sample temperatures during outdoor and laboratory weathering exposures
journal, February 2009


The diffusion time lag in polymer membranes containing adsorptive fillers
journal, January 1973

  • Paul, D. R.; Kemp, D. R.
  • Journal of Polymer Science: Polymer Symposia, Vol. 41, Issue 1
  • DOI: 10.1002/polc.5070410109

Molecular packing and diffusion in polyisobutylene
journal, November 1991

  • Boyd, Richard H.; Pant, P. V. Krishna
  • Macromolecules, Vol. 24, Issue 23
  • DOI: 10.1021/ma00023a040

Quantitative calcium resistivity based method for accurate and scalable water vapor transmission rate measurement
journal, August 2011

  • Reese, Matthew O.; Dameron, Arrelaine A.; Kempe, Michael D.
  • Review of Scientific Instruments, Vol. 82, Issue 8, Article No. 085101
  • DOI: 10.1063/1.3606644