Solar modules are very common all over the world. Unfortunately it is a high energy effort to make them and expensive materials are required.
That’s why we should make them more effective. Most solar panels are fixed in place, which is not very effective because the sun moves the whole day. The solar tracker helps to adjust to the movement of the sun to ensure the most effective position of the solar module. A solar tracker can also be used for solar cookers.
There are some commercial trackers available but it is easy to built it yourself with a minimum of technical skills.
I used strong geared motors and four solar cells (12V, 100mA) for the control device. The system tracks according to the amount of current flowing over the single solar cells. If the sun moves the aluminium sheet casts shade on one solar cell. There are then different amounts of current flowing over the cells and the whole device rotates until the solar tracker is parallel to the sun.
This systems has to be improved because it’s not perfect, but I hope you get the idea.