Salt mist corrosion testing of photovoltaic (PV) modules
|Publication Date:||1 December 2011|
|ICS Code (Solar energy engineering):||27.160|
Scope and object
Photovoltaic (PV) modules are electrical devices intended for continuous outdoor exposure during their lifetime. Highly corrosive wet atmospheres, such as marine environments, could eventually degrade some of the PV module components (corrosion of metallic parts, deterioration of the properties of some non-metallic materials - such as protective coatings and plastics - by assimilation of salts, etc.) causing permanent damages that could impair their functioning. Temporary corrosive atmospheres are also present in places where salt is used in winter periods to melt ice formations on streets and roads.
This Standard describes test sequences useful to determine the resistance of different PV modules to corrosion from salt mist containing Cl- (NaCl, MgCl2, etc.). All tests included in the sequences, except the bypass diode functionality test, are fully described in IEC 61215, IEC 61646, IEC 62108, IEC 61730-2 and IEC 60068-2-52. They are combined in this Standard to provide means to evaluate possible faults caused in PV modules when operating under wet atmospheres having high concentration of dissolved salt (NaCl). Depending on the specific nature of the surrounding atmosphere to which the module is exposed in real operation several testing severities can be applied, as defined in IEC 60068-2-52. For example severity (1) is intended to be used for PV modules used in a marine environment, or in close proximity to the sea. Severities (3) to (6) are intended for PV modules operating in locations where there could be a change between salt-laden and dry atmospheres, for examples in places where salt is used to melt ice formations. Severity (2) is not suitable for PV modules as testing conditions are too weak (this severity is originally intended for products exposed to corrosive environments from time to time that are normally protected by an enclosure) and should be avoided when applying this Standard.
This Standard can be applied to both flat plate PV modules and concentrator PV modules and assemblies.