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Effect of Encapsulant Storage Conditions on the Long-Term Photo-Induced Degradation of EVA in Double-Glass Solar PV Modules
L. Gnocchi, A. Fairbrother, A. Virtuani, C. Ballif
Storage, EVA, Bifacial Module, Glass-Glass-Module, UV Degradation
Photovoltaic Modules and BoS Components
Subtopic: PV Module Design, Manufacture, Performance and Reliability
Event: 37th European Photovoltaic Solar Energy Conference and Exhibition
Session: 4BO.11.6
784 - 788
ISBN: 3-936338-73-6
Paper DOI: 10.4229/EUPVSEC20202020-4BO.11.6
0,00 EUR
Document(s): paper, presentation


Double glass PV modules are expected to be more durable on the long term with respect to modules in a conventional glass/back-sheet configuration. The combination of a rear and front glass cover can in fact delay or completely prevent moisture ingress into the module structure. However, water can be absorbed from the environment by the virgin encapsulant so that storage conditions can be relevant in ensuring the long-time performance of the encapsulant and the PV module. Additionally, in a glass/glass configuration products formed during the aging of the polymeric encapsulant will remain trapped inside the module, affecting the long-term performance of the module. The encapsulant choice is then an important aspect to consider for the encapsulation scheme of bifacial modules. In this work, we investigate the effect of non-optimal storage conditions of EVA and its impact on long-term UV aging. After a total UV dose of 165 kWh/m2 (corresponding to an outdoor exposure of ~2.2 years in a temperate climate the performance of 1-cell mini-modules does not vary. However, preliminary signs of chemical degradation are detectable by means of Raman and FTIR spectroscopy for the non-properly-stored polymer , suggesting that carefully controlling the storage conditions of the polymer may be critical if EVA is used in double glass structures.