Tilt Angle

Tilt angle is the angle at which solar panels are oriented relative to the horizontal ground. The optimal tilt angle for a fixed solar array is generally close to the latitude of the installation location, maximizing the amount of direct sunlight captured throughout the year.

For most of the continental United States (latitudes 25°–48°), the ideal tilt angle is between 25° and 45°. A home in Houston, TX (latitude 30°) benefits from a tilt of about 30°, while a home in Minneapolis, MN (latitude 45°) performs best at around 40–45°. Roof-mounted panels are typically installed at whatever angle the roof provides (most residential roofs are pitched at 15°–40°), and modest deviations from the optimal angle reduce production by only 5–15%. Ground-mount systems offer the flexibility to set the ideal tilt angle precisely. Some advanced ground-mount systems use single-axis tracking to automatically adjust the tilt throughout the day or seasonally. When evaluating a solar proposal, your installer should model the expected production based on your actual roof tilt rather than just using ideal conditions.