What is a solar tracker?

A solar tracker can increase the efficiency of a solar panel by up to 100%! It does this by always keeping the panel perpendicular to the incoming rays of sunlight.

here's an equation to prove this:

P = AW sin θ

P = power generated by the solar panel

A = Area of the solar panel

W = is the solar constant, which is equal to 1340 watts per square meter

θ = the angle of the incoming light

Since sin(90) = 1  you get the best performance out of the panel when it is totally perpendicular.


1 - Arduino Uno w/ ability to program it
1 - Breadboard
1 - 2 axis tracking mechanism (i used a magnifying mirror that swiveled up and down)
2 - 360 deg continuous rotation servos
1 - ball bearing tilt switch or similar
5 - 10k resistors
1 - 5V breadboard power supply
3 - cadmium sulfide light sensitive resistors
soldering iron
vice (optional)


Step 1: The Y-axis

Depending on what you use as a tracking mechanism, yours might be a little different than mine.

I picked up a magnifying mirror from Shoppers normally used for shaving or applying makeup. It had a base and a swivel to tilt the mirror up and down.

I cut off one side of the swivel bracket and replaced it with a servo. I measured so that the shaft of the servo would line up with the swivel point of the mirror. I then had to drill a hole for the servo shaft to fit into.

I used hot glue and zip ties to secure the servo to the base and then the servo shaft inside the hole I had drilled.

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