Solar tracker effectiveness: It's all about availability

Single axis trackers are becoming a common means to achieve greater efficiency from solar farms. Two competing architectures include independent-rows designs and linked-rows designs. Many manufacturers contend that linked-rows design is a superior design because it has fewer components and higher reliability. However, since these systems are repairable, availability is a better measure of superior power production. This paper compares two generic systems using general failure distributions for mechanical hardware and realistic distributions for restorations. The analysis is conducted using sequential Monte Carlo simulations and models the rates of occurrence using Weibull distributions with non-constant occurrence rates, which is consistent with mechanical failure distributions. The analyses include sensitivity studies of the down-time distributions and concludes that the amount of hardware rendered as unavailable during restoration for the linked-rows design impacts the power production (row-availability) much more than the slightly higher unreliability of the independent row design. This study concludes that the linked rows design will, on average, experience 5 to 10 times the days of unavailability as compared to the independent row design.