Solar Panel Angle Calculator by Zip Code: best Tilt & Azimuth Angles
Since solar arrays generate electricity when they're exposed to sunlight, the more sunlight they're exposed to the more electricity they will generate. This means that title angle and orientation of the array is very important.
Solar Panel Angle Calculator
This calculator use a series of global models that will calculate your optimum annual tilt angle based on your latitude and your local climatic conditions.
Based on the data of +14,000 sites spread across the globe from the One Building database. This calculator can be used for any location in the world.
Calculator Notes
- The declination between magnetic directions and your geographic directions (true south and true north) is calculated using the current date from the National Oceanic and Atmospheric Administration (NOAA).
- The seasonal adjustments provided by this calculator are determined by adding 15 degrees to the optimal year-round tilt angle in the winter, and subtracting 15 degrees in the summer.
How to Use our solar panel tilt angle calculator?
1. In the provided text box, enter your city, address, or zip code. Then select your location from the dropdown results.
2. The calculator will automatically start processing the data and calculate the best adapted tilt and azimuth angles for optimized irradiation on your solar panels in your location.
3. Instead of manually entering your location, you can click on the "Use Your Current Location" button. When prompted, click "Allow" to grant the site access to your location.
4. Scroll down on the page to discover your optimal year-round tilt and azimuth angles. If you prefer a simple seasonal adjustment, you'll find also the best solar angles for each season, providing a comprehensive view of optimal panel positioning throughout the year.
Calculate the solar panel angle using general “rules of thumb”
Tilt angles and azimuth angles can be varied from optimum tilt angle without significantly reducing the amount of annual electricity production of solar panels. This is especially true for locations with low latitudes. for that there's the general “rules of thumb” says that for maximize the annual incident solar radiation that your solar panels receive.
If you’re living in the northern hemisphere, your solar panels should be tilted southward. If you’re living in the southern hemisphere, your solar panels should be tilted northward. The tilt angle equal to the latitude of the installation site. This is the ideal configuration that allows you to collect maximum sunlight all year round. For example, Arizona has latitude of 33 degrees. Therefore the tilt angle of your panel should be 33 degrees in order for it to harness maximum energy.
But many homeowners choose to conform the tilt angle to the inclination of their roof. They are concerned about the aesthetics of the installation. Although we will not achieve an optimized configuration in an engineering point of view, such setup serves the user’s needs and wants after all.
Fortunately, solar arrays with tilt variations that fall within 20 degrees will not suffer serious loss. In fact, tilting them some 15 degrees from its optimum angle can have its advantages. During summer, solar panels will not be tilted perpendicular to the sun, but during winter the panels will be oriented perpendicular to the sun for a longer period of time during the day and thus will maximize incident solar radiation.
Similarly, subtracting 15 degrees from your latitude during summer (tilting panels away from the optimum tilt angle) can result in more energy you’re able to generate during summer and less during winter.
The reason solar arrays lose performance at non-optimal tilt angles is because at greater angles to the sun, much of the light simply reflects off the glass surface instead of being absorbed by the silicon semiconductor cells.
Note that the rule of thumb, it is a linear estimates so the rule ignore cloud cover, haze and special local climatic conditions in some regions in the world, especially for regions of latitude higher than 40°N or lower than 40°S. e.g. central and north Europe. so when you looking for the right tilt and orientation for your solar panels use solar calculators.
How to find the optimal solar panel's azimuth angle for your location
Optimum Orientation to Mount a Solar Array
Orientation is the direction the solar array is facing. This also is based on location but in much simpler terms. Basically in the northern hemisphere the orientation should be as south-facing as possible and in the southern hemisphere, as north-facing as possible. That's not to say a west facing array wouldn't generate more power during the late afternoon. It would. But it would also generate very little during the morning to mid afternoon. So in general the more south facing, the better.
What Is a Solar Panel’s Azimuth Angle?
The solar panel azimuth angle is the direction the panels face, and as expressed in most solar calculators online tools it is relative to geographic (true) north - such as PVWatts and Global Solar Atlas tool - or true south such as PVGIS.
The azimuth angle is how many degrees clockwise the solar panels should be from true north (PVWatts) or from true south (PVGIS).
The solar panel’s azimuth angle relates to the geographical locations (the horizon height) in which solar panels will be installed, it take into account local hills or mountains that block the light of the sun during some periods of the day.
Best Solar Panel Azimuth Angle Calculator
The compass shown in our calculator (panels facing) only shows the difference between magnetic south and true south (in the northern hemisphere). In the Southern Hemisphere, it shows the difference between magnetic north and true north.
So. If you live in the Northern Hemisphere, after determining the true south direction of your region, you can face your solar panels directly towards it, or you can then find the optimal solar panels' azimuth angle based on your area. For this, you can use the online tools that use data about ground elevation in your site.
here is a free tools you can use to find the optimal azimuth angle to face your solar panels.
1. Go to PVGIS tool.
2. After determining your location accurately, choose "Optimize slope and azimuth" and click "Visualize results". For example, I choose Austin city, Texas, U.S.
.webp "Solar Panel Angle PVGIS Calculator")
In PVGIS tool, your results are given in degrees from true south. If azimuth angle is positive, it means east of true south. If it’s negative, it means west of true south.
3. You can than use the National Renewable Energy Laboratory's PVWatts Calculator to ensure that the optimal azimuth angle you you found on the PVGis will generate the most electricity.
.webp "PVWatts Calculator to ensure that the optimal azimuth angle you you found on the PVGis will generate the most electricity")
Make sure that you choose the same geographical location in the two tools (latitude and longitude).
4. On the System Info page in PVWatts Calculator start by entering only the tilt angle and leave the azimuth angle as default value (180°), then click "Go to PVWatts Results". I entered “Tilt = 28°” as it giving at the top of this page.
As a result, a 4 kW solar power system in Austin will
generate an estimated
5,914 kWh per year.
.webp "Solar Panel Angle Calculator by Zip Code Tilt & Azimuth")
As you can see from this example, deviations in azimuth angles of 6-10 degrees from true south have small effect, but in some locations can be important, especially if there are local hills or mountains that block sunlight during the morning or late afternoon.
In reality, there are several scenarios that might lead you to deviate from the true south or true north orientation for solar panels.
For example, if there is usually fog during the morning in your location, the optimal azimuth angle might be slightly west of south to enhance exposure to clear skies in the afternoon.
Another reason for such deviation from the true south or true north orientation could be to maximize solar energy production for a grid-connected system during morning or late afternoon (peak times). Read more in our article about East-West vs. South Solar Panels.
Another consideration is to minimize the effects of objects that are very near casting shadows onto your solar panels, such as houses or trees.
Conclusion
This article reveals how to manage your solar solar panels' tilt angle and orientation during installation. These factors are important. They ensure your solar panels receive maximum amount of solar energy through different seasons, especially winter, when there’s little sunlight. With maximum efficiency, the number of panels will be less, resulting in optimum sizing of your solar power system.
Rule of thumb, that tilt angle should be equal to latitude of specific site of a solar panels system can be confirmed for most regions in the world. However, if you live in location with the latitude is higher than 40°N or lower 40°S or your location has very special climatic conditions, and you want the most precise tilt angle possible, we recommend using our solar panel angle calculator.
As you line up your compass to find true south, remember that
it is pointing to magnetic south instead. Corrections must be
made to locate the optimum orientation. To do this, you need to
compensate for the magnetic declination of your site.
Mohamed Bellamine
I'm the blogger behind Goo SolarPower. As a solar engineer, and a strong supporter of renewable energy. I've always been interested in Solar devices. I loves to write articles, guides, and tutorials about solar PV technology. Through goosolarpower.com I want to help people build and understand how solar power systems work.