When determining the best panel angle, several factors affect your final positioning, including time of year, roof structure, and latitude. We cover each contributing factor in detail below.
An optimal angle maximizes available sunlight and ensures your panels absorb as much sunlight as possible. Your panel angle should be close to or equal to your home’s latitude. For most U.S. homes, this angle falls between 30 to 45 degrees. However, the ideal angle varies based on location. In addition, the optimal angle varies during different seasons. As a rule of thumb, reduce your optimal angle by 15 degrees during the summer months and add 15 degrees during the winter months.
Residential rooftop panel installations remain at a fixed angle year-round. A solar installer will consider your home’s latitude and location when determining the ideal angle for your panels.
Existing Roof Design
Most roof designs have a 30- to 40-degree pitch, making it easy to install panels flush against angled roofs. However, some roofs are oriented at a higher or lower pitch, complicating installations.
If your home has a steeper roof angle, installers will place solar panels directly on the roof because they won’t be able to achieve optimal angles with traditional racking mounts. Steeper roofs often fall outside ideal angles for maximum solar absorption. Lower-pitched roofs may require special equipment to compensate for the angle difference. Installing panels flush against this type of roof would reduce energy production and savings.
On homes with flat roofs, installers can use racking systems that tilt the PV panels at an ideal angle. This installation method helps improve solar panel performance but could cause problems. For example, this orientation limits you to certain panel sizes, reducing options for more customized systems. In addition, tilted panels are more susceptible to shading one another and require scattered orientation to avoid this problem. As a result, your solar panel system will be smaller than installations that employ rows of panels across the roof.
Expect an increase in solar installation costs if your roof requires special mounting equipment or complicated panel designs.
Time of Year
The time of year affects the amount of sunlight available for solar panels. Summer offers plentiful sunlight, while colder months bring cloudy and shorter days. Many homeowners offset these changes by installing solar batteries to store excess energy to keep their homes powered year-round. In addition to storage options, homeowners should consider making seasonal angular changes to their panels to improve performance.
Although solar panels produce energy more efficiently during colder months—as they produce more voltage when it’s cold—you’ll typically see a dip in panel production in winter due to fewer full-sun days. The sun is usually lower on the horizon during winter months, making it more difficult for panels to capture the sunlight. In addition, many homes in northern states receive heavy snowfall, which covers panels and lowers their efficiency.
Panels can be adjusted to a steeper angle, ideally around 60 degrees, to counteract these seasonal issues. A “winter angle” positions solar panels to absorb more sunlight, encouraging snow to fall off.