Solar panel angle

Would the power output from a solar array be linearly relative to the cosine
of the angle error between the current perpendicular to the sun angle, and
actual solar panel placement angle ?

Is there other factors or is it that simple? Anybody doen some experiments
or logged some results?

 

A starting resource is:
http://rredc.nrel.gov/solar/

There are three basic components to sunshine:
- Direct Beam, varies as you state
- Diffuse sky, reflections from clouds, the blue sky. There are
several mathematical models for this.
- Ground reflection (albedo)

The output of a solar array is also temperature dependent. Ambient
temperature and temperature rise due to the heating by the sunshine
must be considered, along with cooling by wind.
Bill Kaszeta
Photovoltaic Resources Int'l
Tempe Arizona USA