When I installed a tracking system for the two solar panels that I added to the south wall of my workshop back in June, I did not expect to notice them moving very often. Theoretically they would move incrementally every day to continuously adjust for seasonal solar elevation changes. However, what happens is that whenever clouds pass over the sun on a partially cloudy day the panels tilt down toward a brighter part of the sky in the south. Today I went out with my camera and took time lapse images every 10 seconds for around six minutes. The wind was gusting from 15 to 20 mph, and small dense clouds were moving across the sky fairly quickly. The GIF animation below condenses 6 minutes into 6 seconds and you can clearly see the panels tracking even the slightest cloud cover.
I cannot be certain, but I believe this is squeezing a few more Watts out of those 2 240 W panels that are fed through Enphase M215 inverters that can produce a peak of around 220 W when facing directly into the sun on an ideal day.