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SunTracker 2 Revision 3

A learning platform for optimizing solar systems energy output through alignment to our suns path across the sky.

This is a photovoltaic (PV) solar tracking controller prototype. Solar trackers adjust the PV panel direction, to keep solar panels perpendicular to the sun, maximizing the power output. The increased power output varies, but can be in range of 15~40%, which would be substantial. For places with limited space where increasing solar panel size is not an option, tracking may give the extra energy. I designed and built this prototype to validate basic functionality by tracking the suns horizontal movement (Azimuth angle) across our sky. The main feature of this prototype is a large LED display ring self-aligning to north, which is showing the sun’s position, and is used to develop the controller’s tracking function. Just visualizing the sun’s movement provides insight over things we normally don’t experience consciously, it gives a sense of earth rotation, speed, and our path around the sun.

This project builds a solar tracking device to align solar panels towards the sun for increased power output. These systems exist both commercial and in the maker space, but they are not very common. Today it is often cheaper to just increase the solar panel area. Solar tracking comes with a variety of challenges:

Identify the location of the sun in the sky
Determine if it is worth spending alignment energy to turn panels towards the sun
Mechanical design and maintenance
For 1., identifying the suns location is typically done by either using multi-directional light sensors, picking out the brightest spot in the sky, or by doing location and time specific calculations, determining the sun position from the known path and rotation of our planet. The last method is providing insights about the angle distance required for solar panel alignment, and the reason I choose it as the main method.

For 2., moving and turning solar panels makes only sense if the received energy exceeds the energy that is being spend on tracking. Cloudy days, shallow angles, etc already diminish the energy generation, and solar tracking needs to find the fine balance and trade-off point to make it worthwhile.

Lastly, mechanical design and a robust longterm operation is another concern.

This project, Suntracker 2 Revision 3 focus is on point 1.”

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