This part of IEC TS 63209 includes a menu of tests to use for evaluation of the long-term reliability of materials used as backsheets and encapsulants in PV modules. It is intended to provide information to supplement the baseline testing defined in IEC 61 21 5 and IEC 61 730, which are qualification tests with pass-fail criteria. It may be used by PV stakeholders in conjunction with IEC TS 63209-1 , to provide more extended stress testing of the component materials than can practically be accomplished with PV modules. The data set resulting from testing is used for reliability analysis and is not intended to be used as a pass-fail test procedure. This document addresses polymeric materials in the crystalline silicon module laminates, specifically backsheets and encapsulants in Glass/Glass or Glass/Backsheet modules. Although not specifically addressed, it is expected to also have applicability to thin film technologies.
The included environmental stress tests are intended to cause degradation that is most relevant to field experience, but these may not capture all failure modes which may be observed in various locations.
The individual component standards provide a starting point for testing, and baseline data for reference in this document may be available from a characterization sheet developed in accordance with the Uniform Characterization Forms (UCF) of IEC TS 62788-2 and IEC 62788-1 -1 . Extended tests using the same methods allows for trend analysis.
Additional testing is included to address interactions with other polymeric packaging material, as individual components can perform differently depending on adjacent materials. These tests are designed with BOM-specific coupons and mini-modules, intended to complement the specific module bill of materials used in the IEC TS 63209-1 module tests.
As both test specimen form factor and I-V characteristics can play a role in degradation, some multicomponent tests are designed to use a polymeric stack, while others use mini-modules.
The included stress tests are not designed to test to failure, but to be representative of stress levels of the long-term application.
These tests are not intended to provide service life estimates, or to be indicative of fitness for use in specific climate/mounting configurations. For example, the same module deployed in two different locations or with different mounting methods may degrade in different ways, so a single test protocol cannot be expected to exactly match the performance in both environments; correlation to field will depend upon where and how the product is deployed.
