Exploring suitable damp heat and potential induced degradation test procedures for Cu(In,Ga)(S,Se) photovoltaic modules

Abstract

To ensure a longer lifetime for photovoltaic (PV) modules, many accelerated test standards are being developed or revised. Among the test standards, damp heat (DH) testing in the dark is widely employed to test the module durability. However, in the field, high temperature is usually accompanied by light irradiation. This difference can result in a degradation not observed in the field, especially in the case of Cu(In,Ga)(S,Se) (CIGS) PV modules. To explore suitable test procedures that simulate performance in the field appropriately, we investigated the effects of light irradiation and forward biasing, during DH testing and potential induced degradation (PID) testing of CIGS PV modules. In the case of the CIGS product we have tested, both light irradiation and forward biasing have suppressed degradation in DH as well as PID tests, and no degradation was found after light soaking. These results suggest the needs to add corresponding option(s) to the relevant test standards.

Displacement damage dose analysis of the output characteristics of In0.5Ga0.5P and Cu(In,Ga)(S,Se)2 solar cells irradiated with alpha ray simulated helium ions

“…Since the dosimetry is supposed to be executed in a dark environment, light soaking, which induces recovery from radiation damage, was not carried out prior to the LIV measurements. 21,22) The initial performance values of the InGaP and CIGS solar cells are summarized in Table I.…”

Potential induced degradation of CIGS PV systems: A literature review

“…For modules, studies mainly focus on tracking of the electrical properties upon PID stressing such as I-V characteristics and leakage current measurements. [13][14][15][16][17] Due to the size and the packaging of the field modules, with front and back glass sheets and the encapsulant, it is more difficult to study the nature of the defects and the root-cause of the degradation mechanisms with laboratory based analysis methods. In-depth microanalytic studies for PID have only been reported with laboratory-made CIGS samples, such as mini-modules or cell level samples.…”

Insights into the moisture‐induced degradation mechanisms on field‐deployed CIGS modules

“…[6][7][8][9] However, these analyses are often performed in laboratories on small-scale devices and using artificial aging tests, such as damp heat tests. [7][8][9][10][11][12][13][14] These studies allow for in-depth microscopic analysis, but they are often unable to fully reproduce and represent the real degradation that PV modules undergo in the field. Additionally, the samples made for lab-based analyses can differ significantly from commercial, full-scale PV modules, both in their materials and their design.…”

“…Several reliability experiments on CIGS devices, as well as on other PV technologies, have been conducted to understand the degradation mechanisms linked to water ingress 6–9 . However, these analyses are often performed in laboratories on small‐scale devices and using artificial aging tests, such as damp heat tests 7–14 . These studies allow for in‐depth microscopic analysis, but they are often unable to fully reproduce and represent the real degradation that PV modules undergo in the field.…”