Optimization of the Cost Priority Number (CPN) Methodology to the Needs of a Large O&M Operator

A methodology capable to assess the economic impact of failures in PV projects was one of the main outcomes of the H2020 project Solar Bankability. It was a first attempt to derive a cost-based FMEA (Failure Mode and Effect Analysis) methodology for the PV sector using the metric CPN (Cost Priority Number) instead of the RPN (Risk Priority Number) as typically used in classical FMEA. It was originally applied by developing theoretical scenarios to calculate extreme values for the CPN metric, expressed in Euros/kWp/year. In this study, the methodology has been updated and adapted to the needs of a large O&M operator and applied manually to monitoring data and maintenance tickets of a fielded utility-scale PV plant. The main objective was to identify the adjustments needed to take the implementation of the methodology a step further towards a fully automatized approach. Additionally, the most relevant O&M contractor Key Performance Indicators (KPIs), such as detect, response and repair times, which are the cornerstone of the proposed economic analysis, were revisited and reformulated. Finally, the methodology was further improved by introducing more accurate calculations for Performance Ratio (PR), plant degradation and energy losses.