Degradation processes and mechanisms of PV wires and connectors

Photovoltaic (PV) power plants and their constituent components, by virtue of their application, are exposed to some of the harshest outdoor terrestrial environments. Most equipment is subject directly to the environment and myriad stresses (micro and macro environment). Other aspects including local site conditions, construction variability and quality, and maintenance practices also influence the likelihood of such hazards. Many discrete components, including PV modules, wires, connectors, wire management devices, combiner boxes, protection devices, inverters, and transformers, make up the PV generation system. While there are abundant data that illustrate PV modules and PV inverters to be the major contributors of PV system failures, the mentioned data illustrate the importance of minimizing failures in the often ignored components such as PV connectors, PV wires (both above and below ground), wire splices, fuses, fuse holders, fuse holder enclosures, and wire management devices. With the exception of PV fuses, these components predominantly use polymeric materials. Therefore, it is crucial to understand the typical materials used in components, degradation processes and mechanisms leading to component failure, and their impact on system performance or failure. It further provides some practical considerations, approaches, and methods in addressing the problems with practical solutions in the design to assure the performance of the PV plant over the intended design lifetime.