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What’s the Best Angle for Solar Panels to Get Maximum Output?
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Overview
The output and performance of solar panels will vary based on a lot of factors, including the tilt angle of the solar array. In this article we’ll be covering standard roof tilts and some of the factors that influence overall solar panel efficiency. Tilt angle is defined as the number of degrees your array orients from the ground so it can face the sun.
An easy method for determining solar panel tilt is to match the latitude of your home. This can vary depending on your north-south location, but it generally ranges from 30-45 degrees for homeowners in the continental United States.
Factors such as roof pitch and time of year can affect the overall efficiency of your arrays. Depending on the season, you may experience as much as 8% loss in energy production; however, if you partner with a knowledgeable solar provider like Sunrun, you won’t have to crunch the numbers or adjust the tilt of your panels. Your entire solar system will be designed and placed optimally to accommodate the best performance your home can achieve, year-round.
Why does solar panel angle matter?
To understand how solar panel angle influences performance, it’s helpful to know how a system collects energy.
Solar cells — those little sections on each panel — are made of a special semiconductor material, capable of absorbing radiant energy (or photons)10. However, that semiconductor can only take in a specific wavelength, meaning only a small portion of the light that hits it can be collected.
With so few photons able to enter the solar cell, it's critical that they have as direct an entrance as possible. To enable this interaction, it’s generally wise to point solar panels perpendicular to the sun’s rays.
However, unlike direction, tilt angle varies depending on the seasons. Even with the optimal orientation, you can expect your solar panels to experience some efficiency drop depending on the season5.
Optimal solar panel angle
Unlike direction, the optimal angle for your solar power system isn’t universal across the continental United States; it varies depending on your north-south location.
If you’re curious what the optimal tilt angle for your home would be, first find your latitude measurement2. This will give you the balanced tilt for when the sun is at the earth’s equator. To find your home’s latitude, check out this helpful tool.
For example, if you live in Los Angeles, CA, your latitude averages around 34 degrees N. Therefore, the ideal solar panel angle for your array would be about 34 degrees. However, if you lived in New York City, NY, where your latitude averages about 40.7 degrees N, you might set your tilt angle at 41 degrees.
Remember, you can expect the tilt angles to vary by about 15 degrees as the sun’s location fluctuates with the seasons5.
Using the example from above, Southern California residents can expect their ideal angle to range from 19 degrees in the summer to 49 degrees in the winter. And the spread for New Yorkers spans 25 degrees to 56 degrees.
However, in certain locations, this rule doesn’t apply9. The further you move beyond 30-45 degrees N, the more you have to adjust for the curvature of the earth. Therefore, in states such as Alaska and Hawaii, it’s best to use an online tool to find the optimal angle for your solar panels.
Using an Online Angle Tool
When looking for the right tilt for your solar panels, the latitude rule works in most cases. However, if you live in locations beyond 30-45 degrees, or you want the most precise orientation possible, we recommend using an online calculator.
Tools such as PVWatts or Footprint Hero use highly sophisticated algorithms to calculate several variables including3:
Altitude
Latitude and longitude
Tilt angle
Air temperature and windspeed
Temperature coefficients
Efficiency loss
Radiative transfer
These solar calculators have access to 30 years of meteorological data to provide incredibly precise tilt angles for any location in the world. However, when compared to the latitude rule, their recommendations only result in about %0.7 more output2. So while they’re great tools for installing solar panels at the right angle, they’re not required.
Factors that affect solar panel angle
Latitude
As we’ve mentioned earlier, your location’s latitude plays a major part in determining the best solar panel angle. Across the continental U.S., the optimal tilt can range from 30-45 degrees. However, the further north you live, the more orientation can affect solar panel efficiency.
For example, homeowners in Phoenix, AZ can expect a 7% drop in efficiency for being 20 degrees off optimal. On the other hand, homeowners in Portland, OR may have more than 9% for the same 20 degree difference. Keep this in mind as the seasons change, altering the ideal tilt4.
Roof pitch
Another factor to consider is your home’s roof slope. The average American home ranges in pitch from 4/12 (18 degrees) to 9/12 (37 degrees)6. To find the optimal angle to mount your solar panels, take your base tilt from your latitude and subtract it from your slope. Let’s take a look at some examples:
Home in Miami, FL with 3/12 pitch: 12 degrees
Home in San Diego, CA with 4/12 pitch: 15 degrees
Home in Albany, NY with 5/12 pitch: 20 degrees
Home in Duluth, MN with 9/12 pitch: 7 degrees
Time of year
To reiterate, you’ll see the optimal solar panel angle change with the seasons. Most homeowners can expect +/- 15 degrees in the summer and winter.
With this in mind, the best method for achieving maximal efficiency year-round is to align your tilt angle with the sun’s equatorial position. Any orientation more or less will result in an imbalanced loss of output.
However, this isn’t always detrimental. For example, homeowners in states with Time-of-Use pricing plans may opt for lower than average solar panel angles. This would allow them to produce more energy during the summer when electricity rates are higher.
With so many variables, determining the ideal tilt for your solar panels can feel daunting. But as the #1 home solar company in America, we work with you every step of the way to ensure your system looks great and generates the maximum output. We streamline the process so you can enjoy the benefits and savings of going solar without the guesswork.
Common questions about solar panel angle
What is the best angle for solar panels?
The best tilt angles for solar panels vary depending on where you live. For those residing in the Continental United States, refer to your location’s degree of latitude. For instance, if your latitude is 30 degrees N, the optimal tilt for your solar panels is 30 degrees.
Do seasons affect solar panel angle?
The seasons play a major role in determining the optimal angle for your solar panels. Tilt can change up to 15 degrees in either way during the summer and winter. For example, if your optimal angle is 30 degrees, it can decrease to 15 degrees in July and increase to 45 degrees in January.
Are tracking systems for solar panels worth it?
Tracking systems can follow the path of the sun, allowing your solar panels to output maximum energy. However, they’re costly and difficult to install on a roof, making them more common with ground-mounted arrays.
Is solar panel angle or direction more important?
When considering a solar panel installation, you’ll want to prioritize solar panel direction over angle. While having the optimal tilt can improve output by 5-8%4, orienting your system southward can improve efficiency by up to 30% or more.
Want to learn more about solar panels?
When you find the optimal tilt angle for your solar panel system, you can improve its efficiency by a considerable margin. However, determining that placement for your panels can be both exciting and daunting. Rest-assured, we're here to simplify the process for you.
Our expert Solar Advisors guide you through the complexities and details of solar—from understanding your energy bills, to installation and more. And each Sunrun solar system is custom designed to fit your home’s unique needs.
As the nation's #1 home solar & battery installer, we provide dedicated support from initial system design to powering on your system. Our personalized approach ensures that you make the right decisions about panel placement, enabling you to harness the full potential of solar energy without the stress.
Sources
Fixed Tilt Non-Tracking Solar Panel | TurbineGenerator
Best Angle for Solar Panels: It's Not Your Latitude - Footprint Hero
https://web.stanford.edu/group/efmh/jacobson/Articles/I/TiltAngles.pdf
Solar Array Tilt Angle and Energy Output | Greentech Renewables
Solar Panel Angle: how to calculate solar panel tilt angle?.
Roof Pitch Calculator - Calculates Pitch, Rafter Length, Angle and Slope
What is a solar tracker and how does it work?.
PVWatts Calculator
https://footprinthero.com/solar-panel-angle-by-zip-code
Solar Photovoltaic Cell Basics | Department of Energy