Methodology for a Reliability Study on Photovoltaic Modules

Summary

The Photovoltaïc solar modules for terrestrial applications must be designed for operation with only low power loss during 5, 10 or 20 years in very severe environmental conditions (marine atmosphere, tropical or equatorial climates, rapid changes of temperature, abrasion, mechanical stresses, etc…).

In view to assure a good satisfaction of the user, high resistance to the above mentionned stresses must lead to a well adapted design of the solar module and a good reproducibility of its manufacture. For these reasons, it is necessary to analyse the influence of the technological choices on possible degradation mechanism in use, through a functionnal reliability diagram of a solar module in order to reduce the risk of degradation.

A reliability survey must be set up from both this analysis and the study of climatic and mechanical conditions in the different areas of the world where the solar modules are intended to operate. This program has as its aims:

• to know the effect of these stresses on solar module reliability (specially temperature, humidity, rapid change of temperature, solar radiation, mechanical stresses…)

• to accelerate these stresses and to determine the acceleration laws in more severe conditions in order to set up regular tests and thus to permit rapid correcting action in processing

• to forecast from the above information the probable lifetime of the solar modules under the different environmental conditions throughout the world

• to verify the good adaptation of the solar module to the user needs.