Water-module interaction studies

Abstract

This paper reports on mechanisms by which moisture enters photovoltaic modules and on techniques for reducing such interactions. Results from a study of the effectiveness of various module sealants are reported. quantity of moisture ingress are discussed. It is shown that scribe lines and porous frit bridging conductors provide preferential paths for moisture ingress and that moisture diffusion by surface/interfacial paths is a considerably more rapid process than by bulk paths, which implies that thinfilm substrate and superstrate modules are much more vulnerable to moist environments than are bul k-encapsulated crystalline-silicon modules. Design approaches to reduce moisture entry are discussed.

PV Reliability Development Lessons From JPL's Flat Plate Solar Array Project

“…Key findings included the importance of conductance along encapsulant free surfaces interfaces [15], [16], the strong role of an encapsulant material's ionic cleanliness [17]- [19], and the enormous acceleration (orders of magnitude) associated with humidity level and wet surfaces [15]- [19]. Temperature, as expected, was also determined to be a strong accelerator.…”

“…Based on the research results, draft test methods for wet insulation resistance were drafted and published [17], [20], and design guidelines were developed for limiting electrochemical corrosion in both single-crystal and thin-film modules [16]- [20].…”

“…These we refer to as the reliability technology base that was developed during the FSA tenure. Key technology base contribution areas are noted in Table V and are heavily documented in nearly 400 reports that are organized by technical topic in top-level summaries [1], [2], [16], [21]- [23], [26].…”

Electrochemical and galvanic corrosion effects in thin-film photovoltaic modules

“…The minor differences in measurement results may depend upon major differences in the samples: the previous samples were modules having not only interceding material layers between the A1 metallization and the glass substrate but also intercell zones (scribe lines) which are suspected to be preferential avenues for moisture ingress into TF-PV modules [5].…”

Accelerated and outdoor aging effects on photovoltaic module interfacial adhesion properties

“…7 The adhesive bonds between EVA and various substrates of interest to PV module construction are known to hydrolyze in the presence of moisture. 8,9 The effect of UV on adhesive bonds has been less well studied. Lap shear samples subjected to water vapor and UV have exhibited degradation at the EVA/glass interface.…”