Azimuth

Azimuth is the compass direction a solar panel faces, measured in degrees from true north. Due south is 180° azimuth, due west is 270°, due east is 90°, and due north is 0° (or 360°). In the northern hemisphere, panels facing due south (180°) receive the most total sunlight over the course of a year and produce the maximum annual energy.

A due-south orientation captures the most direct sunlight during peak production hours when the sun crosses the southern sky. However, deviations of up to 30° east or west of due south (150° to 210°) only reduce annual production by about 3-5% — a minor impact that rarely justifies avoiding an otherwise suitable roof face.

West-facing panels (270°) produce less total annual energy than south-facing panels but shift production toward the late afternoon when many time-of-use rate structures charge peak prices. For homeowners on TOU rates, west-facing panels can actually deliver more financial value per kilowatt-hour despite producing fewer total kilowatt-hours, because they generate during the most expensive rate period.

East-facing panels (90°) produce more in the morning and less in the afternoon. This orientation suits households with high morning consumption or areas where afternoon cloud buildup regularly reduces late-day production.

For roof-mounted systems, azimuth is determined by the roof's orientation and is generally not adjustable. When a roof has multiple usable faces, the system design can split panels across orientations — some south-facing for maximum production and some west-facing for peak-hour optimization. Ground-mount systems allow the installer to choose any azimuth regardless of building orientation.