This was a final year project at Manipal Institute of Technology, Manipal. The solar tracking works on the principal of astronomical equations. With the help of the equation it calculates the coordinates of the sun by calculating the elevation and azimuth angle given the latitude, longitude and time zone of a given place. The use of a tracking system greatly improves the power gain from solar radiation. The amount of current a PV panel produces has a direct correlation with the intensity of light the panel is absorbing. Below is a simple drawing of the system:
How does Solar Tracking work ?
The software uses complex mathematical astronomical equations to determine the position of the sun very accurately. The inputs required by the software include the Latitudes, Longitudes and time zone of the location by the user. Other inputs like date, hour, minutes and seconds are taken by the LabVIEW program from the computer system. The software system calculates the azimuth and elevation angle which is fed to the Arduino board wirelessly via XBee chip. Based on the information the Arduino board generates a PWM signal proportional to the angle it gets from the software. The PWM signals are fed to the servo motors to rotate the pan tilt structure on which panel is mounted.
Solar traacking project is divided into two modules: software module and hardware module. Both software and hardware modules have to work in synchronism in order to achieve solar tracking.
One of the unique feature of the project lies in the ‘Sun Trajectory Tab’.This tab provides the information of the sun trajectory with the help of both 2D and 3D graphs along with the current position of the sun. A 2D graph is plotted ‘Elevation Angle’ vs ‘Azimuth Angle’. Whereas the 3D graph gives a more comprehensive outlook to the trajectory of the sun with the directions marked. The trajectory of the sun for both 2D and 3D graph is plotted by simulating the algorithm from sunrise to sunset thus plotting points for each second of the day.
The hardware module comprises of the following components: mechanical components, HS-311 servo motors, Arduino Board, XBee shield, XBee and 1W solar panel. It also is responsible to hold the solar panel and aligned it to the sun. Which helps it to attain the maximum efficiency from the solar panel while wirelessly communicating with the software module.