Array orientation is an important input to any PV performance model calculation. Array orientation is usually described as either fixed tilt or tracked.
A fixed tilt orientation is one that does not move.
A tracked array’s orientation changes with time as the tracker moves the array in an attempt to reduce the angle of incidence between the sun and the array. There are a number of different types of trackers, which are defined by how they move.
Array orientation is described by vectors of the array tilt angle ( ) and the array azimuth angle () for each time interval in the calculation.