Full metadata
Title
Series resistance increase in field degraded PV modules in different climatic conditions
Description
Global photovoltaic (PV) module installation in 2018 is estimated to exceed 100 GW, and crystalline Si (c-Si) solar cell-based modules have a share more than 90% of the global PV market. To reduce the social cost of PV electricity, further developments in reliability of solar panels are expected. These will lead to realize longer module lifetime and reduced levelized cost of energy. As many as 86 failure modes are observed in PV modules [1] and series resistance increase is one of the major durability issues of all. Series resistance constitutes emitter sheet resistance, metal-semiconductor contact resistance, and resistance across the metal-solder ribbon. Solder bond degradation at the cell interconnect is one of the primary causes for increase in series resistance, which is also considered to be an invisible defect [1]. Combination of intermetallic compounds (IMC) formation during soldering and their growth due to solid state diffusion over its lifetime result in formation of weak interfaces between the solar cell and the interconnect. Thermal cycling under regular operating conditions induce thermo-mechanical fatigue over these weak interfaces resulting in contact reduction or loss. Contact reduction or loss leads to increase in series resistance which further manifests into power and fill factor loss. The degree of intermixing of metallic interfaces and contact loss depends on climatic conditions as temperature and humidity (moisture ingression into the PV module laminate) play a vital role in reaction kinetics of these layers. Modules from Arizona and Florida served as a good sample set to analyze the effects of hot and humid climatic conditions respectively. The results obtained in the current thesis quantifies the thickness of IMC formation from SEM-EDS profiles, where similar modules obtained from different climatic conditions were compared. The results indicate the thickness of the IMC and detachment degree to be growing with age and operating temperatures of the module. This can be seen in CuxSny IMC which is thicker in the case of Arizona module. The results obtained from FL
ii
aged modules also show that humidity accelerates the formation of IMC as they showed thicker AgxSny layer and weak interconnect-contact interfaces as compared to Arizona modules. It is also shown that climatic conditions have different effects on rate at which CuxSny and AgxSny intermetallic compounds are formed.
ii
aged modules also show that humidity accelerates the formation of IMC as they showed thicker AgxSny layer and weak interconnect-contact interfaces as compared to Arizona modules. It is also shown that climatic conditions have different effects on rate at which CuxSny and AgxSny intermetallic compounds are formed.
Date Created
2018
Contributors
- Buddha, Viswa Sai Pavan (Author)
- Tamizhmani, Govindasamy (Thesis advisor)
- Alford, Terry (Thesis advisor)
- Srinivasan, Devarajan (Committee member)
- Arizona State University (Publisher)
Topical Subject
- Materials Science
- energy
- engineering
- Field aged photovoltaics Behavior at different climatic conditions
- Interconnects Reliability
- Inter-metallic compounds formation in PV
- PV degradation
- Series resistance increase in fresh and field aged solar cells
- Solderbond degradation
- Solar Cells
- solar panels
- Photovoltaic Cells
- Compound semiconductors
- Semiconductors--Materials.
- Alloys--Fatigue.
- Semiconductors--Defects.
- Semiconductors--Failures.
- Semiconductors--Reliability.
- Semiconductors
- Solar power plants--Climatic factors.
Resource Type
Extent
xi, 51 pages : illustrations (some color)
Language
eng
Copyright Statement
In Copyright
Primary Member of
Peer-reviewed
No
Open Access
No
Handle
https://hdl.handle.net/2286/R.I.51795
Statement of Responsibility
by Viswa Sai Pavan Buddha
Description Source
Viewed on August 12, 2020
Level of coding
full
Note
thesis
Partial requirement for: M.S., Arizona State University, 2018
bibliography
Includes bibliographical references (pages 49-51)
Field of study: Materials science and engineering
System Created
- 2019-02-01 07:06:25
System Modified
- 2021-08-26 09:47:01
- 3 years 2 months ago
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