Reliability of photovoltaic systems using seasonal mission profiles and the FIDES methodology

In areas with hot weather, photovoltaic systems can be used to help relieve the peak demand caused by air conditioning equipment. Users, however, are reluctant to invest in solar technology, arguing that the equipment commercially available is unreliable because it was developed for others environments. In this paper, the reliability assessment of a DC/DC converter aimed at PV applications is presented. The reliability estimation was performed following the FIDES methodology, taking into account seasonal mission profiles developed for five specific sites for which there is meteorological data available. The goal was to identify the most failure prone components, and the dominant stress factors. It was found that the smallest contribution to the failure rate occurs during winter. The largest contribution occurs in spring or summer, depending on the site. In the converter, the most failure-prone components were the diodes, which contributed with about 70% of the overall failure rate.