Azimuth

Azimuth is the compass direction that a solar array faces, measured in degrees from north. In the United States (Northern Hemisphere), a south-facing azimuth of 180° is considered optimal because it captures the most sunlight throughout the day.

True south (180°) maximizes total daily production because the array faces the sun’s path across the southern sky. However, east-facing (90°) and west-facing (270°) arrays still produce significant energy — typically 80–85% of a south-facing array. Southwest-facing arrays (200°–240°) can actually be preferable for homeowners on time-of-use (TOU) rate plans, as they produce more electricity during expensive late-afternoon peak hours. North-facing arrays (315°–45°) are generally not recommended as they produce 30–50% less than south-facing panels. Most residential roofs don’t face exactly south, and solar installers account for your roof’s actual azimuth when modeling system production. Modern design software calculates the combined effect of tilt angle and azimuth to accurately predict annual energy output for your specific roof orientation.