Question

Azimuthal angle solar azimuthal angle and zenith angle 90

Answer 1

1- Tilt angle, β: is the angle between the plane surface and the horizontal (with 0< β <90 for a surface facing towards the equator; 90 < β < -90 for a surface facing away from the equator). 2- Surface azimuth angle, Zs : is the angle between the normal to the surface and the local longitude meridian.