Full metadata
Title
Combined UV-temperature-humidity accelerated testing of PV modules: reliability of UV-cut and UV-pass EVA encapsulants
Description
In the past, the photovoltaic (PV) modules were typically constructed with glass superstrate containing cerium oxide and EVA (ethylene vinyl acetate) encapsulant containing UV absorbing additives. However, in the current industry, the PV modules are generally constructed without cerium oxide in the glass and UV absorbing additives in EVA to increase quantum efficiency of crystalline silicon solar cells in the UV regions. This new approach is expected to boost the initial power output of the modules and reduce the long-term encapsulant browning issues. However, this new approach could lead to other durability and reliability issues such as delamination of encapsulant by damaging interfacial bonds, destruction of antireflection coating on solar cells and even breakage of polymeric backbone of EVA. This work compares the durability and reliability issues of PV modules having glass without cerium oxide and EVA with (aka, UVcut or UVC) and without (aka, UVpass or UVP) UV absorbing additives. In addition, modules with UVP front and UVC back EVA have also been investigated (aka, UVhybrid or UVH). The mini-modules with nine split cells used in this work were fabricated at ASU’s Photovoltaic Reliability Laboratory. The durability and reliability caused by three stress variables have been investigated and the three variables are temperature, humidity/oxygen and UV dosage. The influence of up to 800 kWh/m2 UV dosage has been investigated at various dosage levels. Many material and device characterizations have been performed to ascertain the degradation modes and effects. The UVC modules showed encapsulant discoloration at the cell centers as expected but the UVH modules showed a ring-shaped encapsulant discoloration close to the cell edges as evidenced in the UV fluorescence (UVF) imaging study. The PV modules containing UVP on both sides of cells with limited access to humidity or oxygen through backsheet (covered backsheet with adhesive aluminum tape) seem to experience encapsulant delamination as evidenced in the UVF images. Plausible explanations for these observations have been presented.
Date Created
2019
Contributors
- Arularasu, Pooja (Author)
- Tamizhmani, Govindasamy (Thesis advisor)
- Mu, Bin (Thesis advisor)
- Varman, Arul M (Committee member)
- Arizona State University (Publisher)
Topical Subject
Resource Type
Extent
xi, 75 pages : color illustrations
Language
eng
Copyright Statement
In Copyright
Primary Member of
Peer-reviewed
No
Open Access
No
Handle
https://hdl.handle.net/2286/R.I.53757
Statement of Responsibility
by Pooja Arularasu
Description Source
Viewed on February 17, 2020
Level of coding
full
Note
thesis
Partial requirement for: M.S., Arizona State University, 2019
bibliography
Includes bibliographical references (pages 74-75)
Field of study: Chemical engineering
System Created
- 2019-05-15 12:31:44
System Modified
- 2021-08-26 09:47:01
- 3 years 2 months ago
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