[Gary Dillard]

For a solar tracker running at such a slow output speed, you could probably size the gearbox based on the load (whatever you are mounting that looks at the sun, a PV array?), not the speed. You can pulse the motor at time intervals to decrease the effective input speed (turn it on for a few seconds every 10 -15 seconds) and it will be more than adequate. 360 degrees per day is 0.07 mrad per second. The sun is 9.5 mrad in diameter, so it takes over 2 minutes to move across a focused point along the centerline. Commercial heliostat trackers send position commands every 10 seconds, and they require much higher accuracy than a CPV tracker.