The solar azimuth angle is the azimuth angle of the Sun’s position. It is the angle that the solar panels are facing and is measured in a clockwise direction from north. The direction that your roof faces (in the context of solar installation. The azimuth is measured in degrees, representing the angle between your roof and true north.

This horizontal coordinate defines the Sun‘s relative direction along the local horizon, whereas the solar zenith angle (or its complementary angle solar elevation) defines the Sun’s apparent altitude.

There are several conventions for the solar azimuth; however, it is traditionally defined as the angle between a line due south and the shadow cast by a vertical rod on Earth. This convention states the angle is positive if the shadow is east of south and negative if it is west of south. For example, due east would be 90° and due west would be -90°. Another convention is the reverse; it also has the origin at due south, but measures angles clockwise, so that due east is now negative and west now positive. ( read more here)

The performance of a photovoltaic (PV) installation is affected by its tilt and azimuth angles, because these parameters change the amount of solar energy absorbed by the surface of the PV modules. (read more here)

Setting a panel North towards the sun’s rays will generate the greatest amount of electricity. However, it’s not always practical to face a panel exactly north. This could be because your roof doesn’t have enough space in a north-facing position to fit the panels.

Because the sun moves in the sky throughout the day, it’s important to position each panel so it produces the most electricity when you need it. If you are not at home in the middle of the day, it would be advantageous to produce less overall electricity by facing the panels west or east. This can allow you to spread the generation between the morning and the afternoon, to match when you use electricity. (read more here)

You may also want to read Tilt angle