Originally Posted by

**kiqz** I have an excel calculation which gives me the angles for the horizontal direction and vertical elevation to the sun, for a given time at given longitude/latitude coordinates.

I also know my solar collectors horizontal direction (194,5 degrees) and tilt angle (45 degrees). In other words, I can very easily count the relative horizontal angle between the solar collectors and the sun, likewise also the the vertical relative angle.

However, I'm interested to count **the combined angle**. What could be the equation for this?

Thanks in advance!