Performance of a self-aligning solar array tracking controller

Sandia's advanced SolarTrak control system provides Sun tracking, night and emergency stow, communication, and manual drive control functions, for one and two-axis solar trackers in a low-cost, user-friendly package. The author describes the hardware design features and sophisticated control algorithms, such as a six-degree self-alignment routine and a self-adjusting motor actuation time, that enhance SolarTrak's pointing accuracy and system reliability while at the same time reducing operation and maintenance requirements. Performance measurements taken on operating systems over the past year show that full-day pointing accuracies of better than +or-0.1 have been achieved.<<ETX>>