Factors that Alter the Best Solar Panel Tilt for Your Home
The way solar panels work is by absorbing sunlight and converting it into electricity, usually at an efficiency rate of about 15% to 21%. To achieve optimal absorption rates, light must hit the solar panels at a perpendicular angle, so your aim is to tilt the panels in such a manner as to make this possible.
Several things influence the best solar panels angle for your home. These include:
- The location of your home or business on the globe. More specifically, it’s essential whether you’re located in the southern or northern hemisphere, while the optimal solar panel tilt depends on your approximate latitude (the geographic coordinate that specifies your north-south position on the globe).
- The season of the year. During summer, days are longer and your solar panels are exposed to more sunlight, whereas during winter, days are shorter and your solar energy system has less time to generate power.
- The angle of inclination of the sun. The “height” of the sun in the sky also changes from season to season, which means the positioning of your panels should, too, for better results.
According to these variables, your solar panels will produce different levels of energy at different tilts. It is therefore impossible to state that one solar panels angle is ideal for all installations.
Instead, you can use the following solar panel angle calculators to ensure that you make the most of your specific system throughout the year. Depending on your preference, you can choose a fixed tilt (using a calculator that issues your solar panel angle by zip code) or opt to adjust the tilt two or four times a year for more efficiency. Here’s how.
Solar Panel Orientation
The first thing to consider before adjusting the tilt of your solar panels is the hemisphere you’re in, because this will guide the orientation of your array. If your home or business is in the northern hemisphere (north of the Equator), then the southern faces of your roof will receive the most exposure to sunlight throughout the year. As such, you should position your solar array for southern orientation.
If, on the other hand, you find yourself in the southern hemisphere, your array will benefit from more sunlight if it is fixed on the northern faces of your roof. If your roof is flat or if you desire to place the solar panels on the ground, you can make use of supporting frames in order to achieve the desired orientation and tilt.
If you live anywhere in the United States, for instance, then your house is in the northern hemisphere and your solar panels should be oriented towards the south. You’ll also likely be able to calculate your solar panel angle by zip code.
Solar Panel Angle Calculator: Fixed Tilt
Choosing a fixed tilt for your solar panels means that you never have to move them throughout the year. You simply calculate the average exposure to sunlight regardless of season and you position your array accordingly.
This is perhaps the easiest sun angle calculator to use, as well as the most convenient, because it implies only one equation and no further adjustments following the initial installation of your solar power system. At the same time, however, opting for a fixed tilt is least effective in terms of how much electricity your system will generate throughout the year.
If a fixed tilt works best for you, then this is how you can calculate the right angle for your solar panels.
How to use sun angle calculator for fixed tilt
To use this solar panel angle calculator, you need to know the approximate latitude of your home or business. A very rudimentary formula to calculate the ideal tilt is to add 15º degrees to your latitude for the best angle during winter and to subtract 15º from the latitude for the best angle in summer.
For a more efficient positioning, use your latitude in one of the following equations, depending on your specific situation:
- Latitude below 25º – multiply latitude by 0.87 to find the optimal fixed tilt.
- Latitude between 25º and 50º – multiply latitude by 0.76 and add 3.1º.
If you latitude is above 50º, then the formula is more complex and you should get in touch with an expert for the ideal tilt. If you live in the United States, then your latitude is, most likely, between 25º and 50º. In addition, if you live in a region where you get a lot of snow during the winter, consider positioning the panels at a slightly steeper angle in order to avoid a buildup of snow.
How to find out the best solar panel angle by zip code
Online calculators are available that can determine the best solar panel angle by zip code. The way they do this is by first assessing the latitude associated with your specific zip code and then using it in a rudimentary formula to calculate the optimal tilt of a solar array on your property.
To give you only a few examples, such a calculator would indicate that if you live at 02101 (Boston, MA), the best solar panels angle for your home is 42°. For the zip code 90012 (Los Angeles, CA), the calculator would advise an inclination of 34°. At 10004 (New York, NY), you’d be encouraged to tilt the panels at 41°, while at 20001 (Washington D.C.), the recommended angle would be 39°.
Websites that recommend your solar panel angle by zip code are convenient, but they usually employ simple formulae that do not necessarily ensure maximal efficiency. Still, they remain a quick and easy way to find out the ideal inclination for a fixed tilt in case you do not wish to or have the possibility to adjust your panels throughout the year.
Solar Panel Angle Calculator: Adjustable (x2)
A sun angle calculator that takes into account two changes per year can help your solar energy system achieve higher efficiencies during both winter and summer. This is primarily because the angle of inclination of the sun changes gradually throughout the year and your solar array can be adjusted to receive more sunlight at a perpendicular angle depending on these changes.
All calculations require your hemisphere and latitude and are designed to work effectively for latitudes that are between 25º and 50º, both in the northern and the southern hemispheres. This range includes most properties in the United States, whereas homeowners located outside of these coordinates should get in touch with an expert for more complex calculations.
Sun angle calculator for summer
If you live in the northern hemisphere, adjust your panels to the optimal summer tilt on March 30. Conversely, if your property in in the southern hemisphere, adjust the panels on September 29.
To find out the best solar panels angle for summer, use the following formula:
- Multiply your latitude by 0.93, then subtract 21º.
You’ll find that ideal panel tilts can vary between 2.3º inclination at a latitude of 25º to 16.2º at a latitude of 40º and 25.5º at a latitude of 50º.
Solar angle calculations for winter
To use the solar panel angle calculator for winter effectively, adjust your panels to the winter angle on September 10, in the northern hemisphere, and on March 12, in the southern hemisphere.
To calculate the optimal solar panel inclination for winter, use your latitude in the following formula:
- Multiply your latitude by 0.875, then add 19.2º.
Optimal solar panel tilts will vary between 41.1º inclination at 25º latitude and 63.3º at a latitude of 50º. Generally speaking, in the United States, the ideal inclination for winter is steeper than during the summer because the sun travels lower across the sky during winter months.
Solar Panel Angle Calculator: Adjustable (x4) for Maximal Efficiency
Unlike a calculator that determines your solar panel angle by zip code, a sun angle calculator that permits four changes throughout the year ensures the highest possible efficiency for your solar power system (excluding, of course, the use of a solar tracker).
While not as convenient as a fixed tilt, adjusting the inclination of your panels four times a year, for winter, spring, summer, and autumn can increase the overall efficiency of your array by as much as 10% during the cold season and 5% during summer months.
In other words, if you do not own a sun tracker, but you have the possibility to adjust the position of your panels throughout the year, the outcome is definitely worth the effort.
Solar angle calculations for summer
If you are in the northern hemisphere, adjust your panels to their summer angle on April 18. On the other hand, homeowners in the southern hemisphere should adjust their panels to the same inclination on October 18.
The formula for a more accurate solar panels angle for summer is:
- Multiply your latitude by 0.92, then subtract 24.3º.
This will lead to slight differences compared to a solar panel angle calculator programmed for two changes during the year. For instance, at a latitude of 25º, you’ll want to position the panels slightly away from the Equator, at an inclination of -1.3º. At a latitude of 50º, your solar panels will achieve optimal efficiency during the summer at the inclination of 21.7º.
Sun angle calculator for winter
For optimal results, adjust your solar panels to their winter angle on October 5, in the northern hemisphere, and April 6, in the southern hemisphere.
Use the following formula based on your latitude to calculate the best solar panel tilt for winter:
- Multiply your latitude by 0.89, then add 24º.
The results will vary between 46.3º at a latitude of 25º and 68.5º at a latitude of 50º.
Solar angle calculations for spring and autumn
In the northern hemisphere, you should adjust your panels on March 5, for spring, and on August 22, for autumn. In the southern hemisphere, adjust the panels to the same angles on September 4, for spring, and February 21, for autumn.
The optimal solar panels angle is the same for both autumn and spring because the sun has a similar behavior throughout both of these seasons. To calculate the right angle for your solar array, use your latitude in the following formula:
- Multiply your latitude by 0.98, then subtract 2.3º.
Best results can vary between 22.2º at 25º latitude and 46.7º at 50º latitude.
Have You Considered a Solar Tracker?
Retrofitting your solar array with a solar tracker, if this is possible, is the only way to ensure that the panels are 100% effective in terms of how much sunlight they absorb throughout the day. Using such a device, you can increase the energy production of your solar power system by as much as 40% (although a 30% increase is more common), without ever having to worry about solar angle calculations or manual adjustments.
There are two main types of solar trackers, single-axis and dual-axis. As its name suggests, a single-axis solar tracker rotates back and forth on one axis, either horizontally, vertically, or tilted. A dual-axis tracker, on the other hand, can move in two different directions and can therefore follow the sun both horizontally and vertically at the same time.
Single-axis trackers are more cost-effective and thus more appropriate for utility applications. Dual-axis trackers are slightly more expensive, but their added efficiency makes them ideal for small applications for homes and businesses.
Best Solar Panels Angle: Takeaway
The best tilt for your solar array depends on several factors, the most important of which is the location of your home or business. When you position your solar panels, you can opt for a fixed tilt based on your latitude or you can make two, four, or more adjustments throughout the year depending on both your latitude and the season.
Sun angle charts, sun angle calculators, but also calculators that can provide your solar panel angle by zip code are all easily accessible online, although the information they provide is often simplified.
For best results, consider a solar tracker for your array. If this is not a possibility for you, then you can always make use of the formulae described here in order to increase the efficiency of your solar panels by up to 10%.