Review of O&M practices in PV plants. Failures, solutions, remote control, and monitoring tools

The proper monitoring and operation and maintenance (O&M) of solar photovoltaic (PV) systems are an integral part of the service tasks required to ensure long-term reliability and prolonged lifetime of the installation. In the recent years, with the end of the feed-in-tariff legislation, the PV stakeholders and operators shifted their focus from the design and construction of utility-scale grid-connected PV plants to the development of monitoring and more efficient O&M practices. Service technical personnel have been asked to investigate and resolve unexpected failures of PV systems, whose repair may require specific strategies not initially planned during the design stage. Reliability and, consequently, availability of PV systems are dependent upon a full understanding of failure dynamics, which requires suitable practices to either mitigate or eliminate repeated components failures. Currently, guidelines or technical standards that include PV systems-specific data for reliability assessments are not available, which has caused nonstandardized fault analyses. These differences in practices have somehow compromised the understanding of PV systems reliability at industry level. Based on information gathered from more than 80 PV plants located in Italy, this article outlines remote monitoring techniques that may be used for a general standardization and as a common basis for reliability assessments and an effective O&M. By discussing the most widespread issues, major failures and unexpected events that can occur in PV systems, the authors identify novel remote monitoring techniques to improve both failure reporting and corrective action systems.