The angle of your solar array is an important factor in maximizing your energy production. Depending on where you live, the best angle at which you should install solar panels will change. This is because it’s based on the average position of the sun over your property.
Solar panel angle by zip code
Most solar arrays are installed at a tilt. In order to collect energy more efficiently, solar panels should be angled to face as close to the sun as possible. Photovoltaics produce power when the angle at which the sun’s rays hit the panel surface (the “angle of incidence”) is small, or when light strikes the panel as close to perpendicular as possible.
For the vast majority of U.S. property owners, the ideal angle for a solar panel installation is close or equal to the latitude of your home (on a south-facing roof).
Best Solar Panel Angle By Zip Code
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Why does the angle of a solar panel matter?
Solar panels produce electricity when sunlight hits their surface, and they produce the most energy when that sunlight is exactly perpendicular to the panel face. Therefore, the best angle for your solar panels is the one that allows the panels to get the most direct, perpendicular light.
While the sun is in a higher position in the sky during the summer and lower position during the winter, it has an average position right in between the two seasons. By tilting your solar panels the same angle as the latitude of your home (which means pointing your panels at that average position), you are ensuring that you will get the maximum average output from your solar system throughout the year.
What about solar trackers?
The sun’s position is constantly moving throughout the year, and the only way to always have your solar panels angled perfectly is to install a solar tracking system. Solar trackers follow the sun as it moves slightly, which will bump up your energy production. If you are considering a ground-mounted solar system a solar tracking setup may work.
For the majority of solar shoppers, a rooftop system is the lowest cost and doesn’t take up space on the ground, and solar trackers can’t easily be installed. Solar trackers are generally only used in commercial solar projects that can dramatically increase production with a tracking system.
Other factors affecting solar panel angle
Your latitude isn’t the only factor in determining what angle your solar panels should be at. Here are a few things to consider when determining the best tilt for a solar array.
Existing roof design
It would be great if everyone had a roof that was angled exactly the same as their latitude, but every property is unique. Many roofs are going to have slopes between 30 and 40 degrees, which means that solar panels can lie flush against the roof and produce enough electricity for attractive returns.
If you are trying to install solar panels on a steep roof, it may not be possible to place panels at the optimal tilt with traditional racking systems. Because the steep angle of your roof might already be higher than the optimal angle for production, the best you can do is lie your panels flat against the roof. Low angle roofs will also face obstacles when it comes to solar panel installation and may require specialized racking if you’re looking to tilt them at the optimal angle. Placing panels flush against these types of roofs will mean less electricity production, which will lead to reduced solar savings over time.
In the case of a flat roof, solar installers will usually opt to use racking systems that mount your panels up at an optimal angle. While this allows for your panels to face the sun more directly, you may be limited when it comes to your system size. Tilting panels up on a flat roof will lead to the panels shading one another unless you space and stagger the rows of panels out on the roof. As a result, you can’t install as many panels as you would otherwise be able to if the solar panels were flush against the surface.
Regardless of whether your roof is steep or flat, it’s always best to have a professional solar installer mount the panels on your roof to ensure optimal production and optimal safety.
Solar panels work well in the winter, but you will typically see a dip in total energy production during particularly bad winters due to snow covering your panels and reducing their power output. One way to counteract winter production dips is to install your panels at a lower angle than your latitude. By doing this, you are setting up your panels to perform more efficiently in the winter because they will more directly face the sun as it shines from a lower point in the sky. However, installing panels at angles of around 15 degrees or less can backfire, as snow won’t easily fall off of your array. This will lead to long-lasting snow cover and decreased electricity production.
Orientation of the panels
While the angle of your solar panels is important, a more important factor in your energy production is going to be the direction your panels face. For the best results, solar panels should be oriented towards the south. This is because the sun is always in the southern half of the sky in the northern hemisphere. You can still have an effective solar installation with arrays facing east or west but may need to install a larger system to meet the same amount of electricity production that a southern-facing array would have.
It’s not a good idea to install your panels to face a suboptimal direction even if it means the best tilt possible. In Boston, a solar array at 30 degrees south is still going to produce more electricity than tilted at 42 degrees and facing north.
The best way to find a high-quality solar installation is with EnergySage
Determining the ideal solar panel angle for your property is straightforward, but you’ll need a certified professional to recommend equipment and install your solar system. On the EnergySage Solar Marketplace, you can receive free quotes for a solar installation from our qualified, pre-vetted installers across the country who will design and optimize a solar energy system for your unique property. If you are interested in talking to potential installers about the angle of your solar panels, simply leave a note on your profile indicating your interest.