As part of a thesis project, Belgian student Bruce Helsen built a dual-axis tracker for optimizing solar panel use. Although adding a tracking system to a larger installation can be pricey (and likely not the most cost-effective option), it can certainly come in handy for smaller units.
Helsen’s dual-axis tracker fits two 12V 150W solar panels for a 300W peak output, and has a few key features: it turns to make sure the panels are aligned with the sun for as long as possible, it measures the panels’ voltage and current then calculates the generated power and energy, and it sends that data from the monitor to ThingSpeak for analysis and logging. There’s also an LCD to display the readings.
The panel’s two axes are controlled by a pair of inexpensive linear actuators. It uses an Arduino Mega for a brain, and an ESP8266 for transmitting the data over to the cloud. Light direction is detected by a homemade light sensor housed inside an industrial lamp enclosure. A 3D-printed crossbeam separates the sensor into four quadrants, with a light-dependent resistor for each. By comparing the average LDR values, the panel is able to point in the best direction.
Looking to monitor your solar energy? Check out Helsen’s project page here.