Acceleration Factors for Combined‐Accelerated Stress Testing of Photovoltaic Modules

Abstract

Numerous field failures are observed in photovoltaic (PV) modules that pass standardized design qualification and type approval testing. Standardized tests are typically mechanism-specific and only developed after the failure mode has caused extensive trouble in the field. For example, technical papers emerged in 1977 that showed PV module susceptibility to system voltage in humid conditions, presently referred to as potential-induced degradation (PID). [1,2] Methods for PID testing were proposed in 1978 but not widely implemented. [3] While some work continued in thin film technology, [4] the phenomenon was largely ignored until field failures with various PID types were extensively reported. The PID issue led to a great deal of financial cost in the 2005 to 2015 timeframe. [5,6] Field-relevant PID test methods were agreed upon and standardized in IEC 62 804-1 in 2015 [7] and incorporated into IEC 61 215 qualification testing in 2021, [8] which is 44 years after the first publications about PID. Faulty products were produced, shipped, and sold with many consumers unaware of the issue. Other examples of degradation modes discovered after extensive shipments of PV modules include light and elevated temperature induced degradation (LETID), an important degradation mode in modules with passivated emitter and rear contact (PERC) cells, [9][10][11] and cracking of polyamide (PA) and certain polyvinylidene fluoride (PVDF)-based backsheets. [12,13] With the discovery of new degradation or failure mechanisms, numerous tests were added to comprehensively examine these

Accelerated Stress Testing of Perovskite Photovoltaic Modules: Differentiating Degradation Modes with Electroluminescence Imaging

“…For commercial PV, passing the IEC 61 215 qualification test means a module is "capable of withstanding prolonged exposure outdoors," [27] and further related testing has been used to estimate degradation rates and identify weaknesses of module designs. [28][29][30] Using accelerated stress to simulate severe environmental conditions and evaluate a module's response to individual stress factors can reveal distinct degradation mechanisms which may not be separately observable under combined stressors outdoors. [9,15] For example, accelerated stress testing using damp heat has shown MHP mini-modules retaining more than 90% of their initial power conversion efficiency (PCE) for over 1000 h, and up to 3000 h. [4,14,18] These studies demonstrate effective encapsulation techniques that enhance MHP module durability.…”

Potential‐Induced Electrochemical Corrosion in Crystalline Silicon Solar Cells

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Corrosion is one of the significant degradation modes for crystalline silicon photovoltaic (c-Si PV) modules. [1][2][3][4][5][6][7] The major factor causing corrosion degradation of c-Si PV modules is moisture and atmospheric gases, which can permeate into glass/ back-sheet modules and glass/glass modules through permeable back-sheet and the edge of modules, respectively. [8,9] Once water vapor and gases come into PV modules, ethylene-vinyl acetate (EVA) encapsulant will be decomposed to generate acetic acid.

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