Tracking the sun

Facing the sun

Interactive Simulation
Interactive Simulation

PV modules receive more energy if they  directly face the sun. It is a simple geometric formula. The energy received from direct radiation is proportional to the cosine of the angle between the sun’s rays and a vector perpendicular to the panel. For example, if the solar rays are at a 45 ° deg angle to the panel the energy yield will be cos(45 °) or only about 70% of the solar energy available. If the panel is perpendicular to the sun, cos(0°)=1 and the energy received is maximum. At the other hand, (and obviously) is the panel is parallel to the sun ray, the energy is zero – cos (90°) = 0 .
Regardless of their orientation, the PV modules will still receive some of the diffuse solar energy, scattered by the atmosphere.
Run this interactive simulation to visualize the solar energy yield from five different mounting systems: Fixed, Horizontal Axis Tracker (HAT), Polar tracker, Vertical Axis Tracker (VAT), Two-axis (full tracking).
The results clearly indicate the benefits of tracking the sun.


The CDF Player Plug-in must be installed to run this simulation.