There are various methods to detect failures and defects in a PV system. This article explores the positive and negative aspects of these methods. Failures & Defects in PV Systems: Typical Methods for Detecting Defects and Failures.
A dual-axis tracker is a device that tracks the sun's movement along two axes (horizontal and vertical) to maximize the amount of sunlight captured by solar panels.
Solar panels are rated for hail impact which is roughly the impact of a 1" hail ball striking the panel at 52 mph. The tempered glass protects the solar cells under this type of impact.