Dual axis trackers allow for optimum solar energy levels due to
their ability to follow the sun vertically and
horizontally. No matter where the sun is in the sky, dual axis
trackers are able to angle themselves to be in direct
contact with the sun.
Dual axis trackers have two degrees of freedom that act as axes of
rotation. These axes are typically normal to one
another. The axis that is fixed with respect to the ground can be
considered a primary axis. The axis that is referenced to
the primary axis can be considered a secondary axis. There are
several common implementations of dual axis trackers.
They are classified by the orientation of their primary axes with
respect to the ground. The orientation of the module
with respect to the tracker axis is important when modeling
performance. Dual axis trackers typically have modules
oriented parallel to the secondary axis of rotation.