Title:	Viscoelastic Study of PV Module Encapsulant for the Prediction of Thermal Durability
Author(s):	T. Aoyagi, M. Kuramitsu, E. Yamamoto, S. Ogawa
Keywords:	Encapsulation, Photovoltaic (PV) Module, Durability
Topic:	Components for PV Systems
Subtopic:	PV Modules
Event:	26th European Photovoltaic Solar Energy Conference and Exhibition
Session:	4AV.1.1
Pages:	3295 - 3297
ISBN:	3-936338-27-2
Paper DOI:	10.4229/26thEUPVSEC2011-4AV.1.1
Price:	0,00 EUR
Document(s):	paper

Abstract/Summary:

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In this paper, dynamic viscoelastic analysis of PV module encapsulant was carried out for the prediction of the thermal durability of long time use. Polyolefin(PO) sheets cross-linked by electron beam radiation were used for the study, and steady state shear rate was estimated from the dynamic viscoelastic analysis. On the other hand, accelerated creep behavior was experimentally determined by laminated sheets (glass/encapsulant/dummy cell/encapsulant/back sheet) exposed at T=120 and a pitch angle of 80 degree. Comparing the steady state shear rate estimated by the dynamic viscoelastic analysis and the velocity of the creep test, high correlation between both results was found. This result suggests that the complex creep behavior of the real PV module can be described by the simple viscoelastic analysis, and the displacement of PV cell under the condition of creep test can be estimated by this analysis. Furthermore, based on the estimation, we found that the PO sheet have sufficient durability in terms of thermal characteristic as material for encapsulation.