Title:	Are PV-Module Backsheets with an Outer Fluoropolymer Layer the Better Solution?
Author(s):	J. Kriening, M. Engel, D. Geyer, D. Stellbogen, P. Lechner
Keywords:	Degradation, Reliability, PV Module
Topic:	Photovoltaic Modules and BoS Components
Subtopic:	Materials for PV Modules, Durability, Reliability and Accelerated Testing Methods
Event:	8th World Conference on Photovoltaic Energy Conversion
Session:	3DO.17.5
Pages:	580 - 584
ISBN:	3-936338-86-8
Paper DOI:	10.4229/WCPEC-82022-3DO.17.5
Price:	0,00 EUR
Document(s):	paper

Abstract/Summary:

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The aim of this work is to determine if polyethylene terephthalate (PET)-core backsheet laminates with an outer weather protection layer based on fluoropolymers are advantageous or necessary to guaranty adequate longterm stability and electrical safety of PV-modules. After observing a manifold of severe issues with coextruded polyamide backsheets (trade name AAA) [1, 2, 3] fluoropolymer protected backsheets gain back significant popularity. However, it is increasingly under discussion, whether fluoropolymers are really of low concern for human and environmental health [4]. More specifically, concerns are expressed regarding the safe disposal of fluorochemical polymers at the end of their life cycle and the rather limited options for recycling. Our approach was comparative testing of field aged modules with and without fluorochemical outer layer backsheets. In the test laboratory Solab of ZSW Stuttgart the modules were visually inspected, the STC power and electrical insulation was measured and the embrittlement of the backsheet was evaluated. While we observed some differences concerning the visual anomalies, the STC power and the electrical insulation of the modules as well as the embrittlement of the related backsheets indicate that fluorine-free outer layer polymers protect the PET core of the backsheet just as well as fluorochemical polymers.