Polymeric backsheets form the outer protective layer of most crystalline and multi-crystalline silicon cell photovoltaic panels. The mechanical, electrical, optical and chemical properties and durability of these backsheets are critical to the long term reliability, durability and safety of the photovoltaic modules. The stability of these backsheet properties is typically determined based on accelerated testing using individual stresses. However, the impact of multiple stresses applied sequentially or simultaneously can lead to changes in materials properties that are more predictive of performance in the field. An important consideration in the development of accelerated test protocols is the level and duration of the stress, including temperature variation, light intensity & spectral power distribution, humidity, rainfall and powered module current. In this paper, we discuss observations of the aging and degradation of solar panel from the field. Then how these changes correlate to accelerated testing results, and how accelerated tests can be modified to better match observations in the field.
Photovoltaic modules in the outdoor environment are subjected to a wide range of stresses which can operate simultaneously and sequentially and can vary based on climate and installation.These stresses can include temperature, temperature variation, localized heating, humidity, moisture (rain, snow, humidity, condensation), weathering, mechanical stress, abrasion and internal electric fields. These multiple stress make prediction of service lifetime challenging. Frequently resistance to an extended single stress is improperly used to assess durability. We have used sequential and simultaneous multistress exposure of materials and modules to better predict the synergistic effects of these stresses on module performance. We have also assessed the change in component materials properties to better understand performance changes. Finally, we compare these results to inspection of modules from the field to validate the test methods proposed.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.