My design school teacher said they used clocks to move sun-trackers back in the 1930's. You do have to adjust the inclination by hand every day or so.Make a panel with a ring of of photo-sensors close around a rod perpendicular to the center. When it casts a shadow you know which way to turn until it doesn't. That needs no MCU at all.
A ramp with a mechanical clock like device? aim the panel in the morning sun at the highest point of the ramp an during the day it "ticks" to the lower end?possible?
Lets say I have 2000,000 solar panels.