I'm doing a project where I have to rotate solar panels to track the sun, I have found many websites where you can type in your information and they tell you everything I need. My problem is I don't understand where they get the information from! various sites have lists of equations but they don't give enough information for me to understand If some one knows how to do this I would really appreciate it.

The information I expect to get from June 21 2009 @ 12:15 (or 11:15 depending on day light savings) is an azimuth angle of roughly 150 degrees

If possible the steps between showing the equations would be very useful