SOLAR TRACKER FAILURE DETECTION OF SONDA PETROLINA SOLARIMETRIC STATION

This document presents a method to infer solar tracker probabilistic reliability indices from Solarimetric Stations measurements. The methodology collects global, beam, and diffuse irradiances data. It establishes a usual criterion to determine solar tracker failure days, based on the premise that when the tracker stocks, pyrheliometer and shadow ball do not move, implying that global irradiance is almost equal to the diffuse along the day, and beam irradiance is very low. The failures are reanalyzed, and a two-parameter Weibull distribution fits the reliability and failure rate curves considering the monotonic behavior in the operation times. The procedure was applied for the SONDA solarimetric station in Petrolina, state of Pernambuco, Brazil. Results show a mean time between failures lower than 18 months, indicating that an annual maintenance rate is appropriate to avoid this type of failure.