Solar energy is rapidly gaining momentum as a sustainable and reliable source of power for homes, businesses, and communities worldwide.
In fact, the global outlook for solar power is also promising, with the International Energy Agency forecasting that global solar generation could surpass natural gas by 2026 and coal by 2027.
However, the efficiency of solar panels isn’t solely dependent on the availability of sunlight— it also hinges significantly on the angle at which panels are installed.
As such, understanding the optimal angle for solar panels is crucial for maximising energy absorption and harnessing the full potential of the technology.
Optimal angle for solar panels
The angle at which one’s solar panels are set in place plays a significant role in their performance and energy production.
The tilt angle of solar panels determines the angle at which they are inclined relative to the ground. An optimal angle allows solar panels to extract the maximum amount of sunlight throughout the day.
Generally, solar panels should ideally be tilted to face the sun directly to ensure optimal energy absorption. However, the optimal angle for a solar panel may differ throughout the time of year, and by latitude.
Nonetheless, the more sunlight each solar panel can convert into energy, the higher the system’s total electricity output. Therefore, the angle of a solar panel directly impacts its efficiency and energy production. Thus, making it a crucial factor to consider when installing a solar panel system
Factors influencing the best angle for solar panels
Characteristically, solar panels are most efficient when receiving sunlight perpendicularly. However, several factors may influence the best angle for a solar panel, including:
Geographical location
The geographical location of a solar installation significantly impacts the optimal angle for solar panels. For context, areas closer to the equator typically benefit from a more direct angle of sunlight throughout the year.
Whereas regions further from the equator may require adjustments to accommodate for lower sun angles during certain seasons.
Seasonal variations
In practice, the angle of the sun changes throughout the year because of the Earth’s axial tilt. So, iteratively adjusting the tilt of solar panels according to the seasons can appreciably optimise energy absorption.
For example, a steeper angle in the winter can help shed snow and increase energy production.
Roof slope
The slope of your roof may impact the optimal angle for solar panels. Roof pitch, measured in terms of the rise and run, can affect the amount of sunlight that reaches the panels.
The relationship between roof slope and solar panel angle should be considered for optimal energy production.
Also read: Can you install solar panels on flat roof?
Determining the best angle for solar panels
The best ways to determine the best angle for solar panels to achieve optimal energy production are:
Solar panel angle by latitude
One effective way to determine the best angle for solar panels is to consider the latitude of your location. The latitude rule suggests that the optimal tilt angle should be approximately equal to your latitude. However, this rule can be further refined based on the latitude range.
- For latitudes below 25°, multiply the latitude by 0.87 to determine the optimal angle.
- For latitudes between 25° and 50°, multiply the latitude by 0.76 and add 3.1 degrees to find the ideal tilt angle.
- For latitudes above 50°, additional considerations and calculations are required.
Using solar panel tilt angle calculator
To achieve the most accurate and precise solar panel angle, one can utilise online calculators specifically designed for this purpose.
These calculators take into account various parameters, such as latitude, longitude, tilt angle, air temperature, and wind speed, among others, to provide highly accurate recommendations. Some popular solar panel tilt angle calculators include PVWatts and Footprint Hero.
If you’d like to calculate the optimal angle the old-school way, there are two methods according to Sinovoltaics. The first involves calculating the optimum tilt angle by adding 15 degrees to one’s latitude during the winter —and subtracting 15 degrees from one’s latitude during the summer. For instance, if one’s latitude is 34°, the optimum tilt angle for their solar panels during the winter season should be 34° + 15° = 49°.
The summer optimum tilt angle, on the other hand, shall be 34 – 15 = 19°. The second method, an improvement of the first, gets the optimum angle by multiplying the latitude by 0.9 and then adding 29°. In the case of a latitude of 34°, the tilt angle will be (34 multiplied by 0.9) + 29 = 59.6°.
This angle is 10° steeper than in the general method. However, it is highly effective at tapping the midday sun (which is hottest in the short winter days). For summer, the tilt angle is calculated by multiplying the latitude by 0.9 and subtracting 23.5°.
In the above example, this angle would be (34 * 0.9) – 23.5 = 7.1°. For optimum tilt angles during spring and fall, 2.5° is subtracted from the latitude.
Adjusting angles according to seasons
Seasonal disparities in the angle of the sun can noticeably impact the performance of solar panels. To maximise energy output, solar panels should have their tilt angle adjusted at least twice yearly. The following table provides the best dates for adjusting the tilt angle based on the hemisphere:
| Hemisphere | Summer Angle Adjustment | Winter Angle Adjustment |
| Northern Hemisphere | March 30 | September 29 |
| Southern Hemisphere | September 10 | March 12 |
To get the ideal summer angle for latitudes between 25° and 50°, take the latitude and multiply it by 0.93, then subtract 21 degrees. The winter angle is equal to 19.2 degrees plus the latitude multiplied by 0.875.
These modifications maximise energy production by capturing the maximum amount of sunlight during each season.
Frequently Asked Questions (FAQs)
Do solar panels work better at an angle?
Yes, solar panels typically work better when installed at an angle compared to flat installations. Angled panels are better positioned to capture sunlight effectively, resulting in increased energy production.
What is the best direction for solar panels?
The best direction for solar panel installation in the Northern Hemisphere is true south, while in the Southern Hemisphere, true north is preferred.
True direction should not be confused with magnetic north, as there may be variations depending on your location. So, it is essential to correct the difference between true and magnetic north to ensure accurate panel orientation.
Are there different solar panel angles for different roof types?
Yes, the optimal angle for solar panels may vary depending on the type of roof. For example, flat roofs may require different mounting systems to achieve the desired tilt angle compared to sloped roofs. Installers should assess the unique characteristics of each roof type to determine the most suitable angle for solar panel installation.
What angle should a solar roof be?
Solar roofs should be angled according to the latitude of your location, as well as seasonal variations. The recommended angle can be determined using the latitude rule or by using solar panel angle calculators. A properly angled solar roof ensures maximum energy production throughout the year.
At what angle do solar panels stop working?
Solar panels do not stop working at a specific angle. However, extreme angles, such as a completely flat or vertical orientation, can significantly reduce their efficiency.
To ensure optimal energy production, it is crucial to set the tilt angle within the recommended range based on your location.
Which tilt angle gives the highest annual energy output?
The tilt angle that gives the highest annual energy output depends on various factors, including geographical location and seasonal variations.
Adjusting the tilt angle of solar panels according to the seasons, as discussed earlier, can help achieve the highest annual energy output by maximising sunlight absorption.
What is the solar panel tilt single formula?
The solar panel tilt angle formula varies depending on your location and the desired adjustment.
The formulas mentioned earlier such as multiplying the latitude by a specific factor and adding or subtracting degrees, provide a simplified approach to determining the optimal tilt angle.
However, more precise calculations may be required for specific applications and locations.
What is the best angle for south-facing solar panels?
South-facing solar panels in the Northern Hemisphere should be tilted towards the true south in order to capture the maximum amount of sunlight throughout the day.
The optimal angle may be determined by utilising the latitude rule or by using solar panel angle calculators for a more accurate recommendation.
Is angle the most important factor in solar panel installation?
While the angle of solar panels is crucial for maximising energy absorption, it’s just one of several factors that influence overall performance.
Factors such as panel orientation, shading, and system efficiency also play significant roles in determining the effectiveness of a solar installation.
Conclusion
Ascertaining the best angle for solar panels is a critical step in maximising energy production and optimising the performance of one’s solar system.
Generally, the tilt of the panels affects the exposure of the panels to direct sunlight. This is because panels collect solar radiation most effectively when the sun’s rays are perpendicular to the panel’s surface.
Furthermore, factors like geographical location, seasonal variations, and roof slope may impact a solar panel’s ability to achieve the highest efficiency and output.
Overall, the angle of the panels may be iteratively adjusted to maximise energy production annually..
