Casting light on backsheet destruction

Mar 12, 2020 01:07 PM ET
  • A U.S. research study group has actually uncovered that backsheets are most influenced by fracturing and also destruction on internal layers, therefore locations often tend to come to be much more inflexible. The researchers have actually additionally found that destruction is sped up by chemicals coming down from the solar cells' EVA encapsulant to the backsheets themselves.
Casting light on backsheet destruction
Image: NIST

Researcher at the U.S. Department of Commerce's National Institute of Standards as well as Technology assert to have actually lost a lot more light on the source of backsheet destruction in photovoltaic panels.

In the research study Drivers for the fracturing of multilayer polyamide‐based backsheets in area photovoltaic components: In‐depth destruction mapping evaluation, released underway in Photovoltaics, the scientists go over extensive deterioration mapping of PV module backsheets.

Various examinations

The scientists have actually attempted to recognize the root causes of early splitting in polyamide-based backsheets as well as just how polyamide products engage with photovoltaic panel design. They have actually made use of chemical and also mechanical examinations on backsheet examples from photovoltaic panels utilized in the United States, China, Thailand and also Italy. The majority of them reveal clear indications of early splitting, they claimed.

Their evaluation has actually additionally revealed that the backsheet locations most impacted by splitting as well as destruction are internal layers. "Curiously, one of the most fragile locations got on the internal side of the sheets," stated Xiaohong Gu, a co-author of the paper.

EVA encapsulant

The researchers have actually additionally made an additional fascinating exploration. They have actually discovered that backsheet deterioration is sped up by harmful chemicals from the solar battery encapsulant-- the ethylene plastic acetate (EVA) movie-- dropping onto the backsheets.

The researchers stored a number of polyamide remove in vials of acetic acid and after that, after 5 months, assessed the level to which they had actually rotted, compared to strips positioned in either air or water. Splits matching those from the weather-beaten backsheets showed up externally of the plastic strips subjected to acetic acid. The splits were a lot even worse than those on the examples that had actually been revealed to air or water, the scientists stated.

" The examination revealed the first‐time straight proof that acetic acid can mainly increase the chemical deterioration as well as assist in the breaking of the polyamide internal layer," the scientists ended. "This research recommends that the area fracturing of polyamide‐based backsheet can be credited to the mixed results of chemical destruction and also physical reconstruction (chemi‐crystallization) under cyclic thermomechanical stress and anxieties."

The researchers likewise kept in mind that panels created in the 2010-12 duration mainly made use of polyamide-based backsheets.

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