If you’re thinking about installing solar panels on your roof, you might be surprised at how many variables can affect the performance of your panels. While various factors can make a roof more or less compatible for solar, other factors have a minimal impact on the overall solar energy production. Two of the main roof factors that can impact the performance of your solar energy system is solar panel orientation and angle.
Here’s what you need to know about the best orientation and angle for your solar energy system:
Solar Panel Orientation
Your roof direction is a primary factor in determining how much sunshine your panels will be exposed to throughout the day. True south and true north both face the Earth’s axis and don’t align with the Earth’s magnetic poles.
For homeowners in the Northern hemisphere, the best direction for solar panels to face is south. All of us in sunny California fall into this category and should avoid panel placement facing North. When you position solar panels based on true south and the azimuth angle (the sun’s angle in relation to true north and true south), you get the most optimized orientation for production and efficiency.
Solar Tip: If you’re not sure which direction your roof faces, you can look your address up on Google Maps. The grid shows which direction is true south and you can compare that to your rooftop’s direction on the satellite imagery.
Optimizing Your Solar Panel Orientation
As mentioned above, solar panels will produce more energy when they face south in direct sunlight. The reality is that many homeowners don’t have enough south-facing roof space available due to a variety of factors that include obstructions on the roof or trees that shade the area needed. This is while you see many homes with panels placed on the south, east and west planes of their roof. In general, solar panels that face either directly east or west produce about 20% less electricity than if they faced south. While you’ll still save money, you may have to install a few more panels to cover all of your home’s electricity usage with solar compared to a south-facing system.
For homeowners in the northern hemisphere, even though it’s possible to install panels on the north side of your roof, it’s actually the worst location for solar production. If north-facing roof space is all you have available, you’ll most likely need to utilize special mounting so your panels oppose your roof’s slant in order to generate energy from the sun. As a result, the panels won’t sit flush with the roof and may still produce less electricity.
Solar Panel Angle
The angle of your solar panels is an important aspect to consider when designing your system. Solar panel angle is also known as the vertical tilt of your solar panel system. For example, a solar panel array that’s perpendicular to the ground has a 90-degree angle tilt.
To harness solar power more efficiently, solar panels should be angled to face the sun as closely as possible. Photovoltaic panels produce power efficiently when the angle at which the sun’s rays hit the panel surface (known as the “angle of incidence) is small or when light hits the panel as close to a perpendicular angle as possible. As a result, the best solar panel angle allows your panels to get the most direct, perpendicular sunlight.
What Factors Affect Your Optimal Solar Panel Angle?
A number of factors will alter the optimal angle of your solar panels. Here are some important things to consider to determine the best tilt for your solar panel array:
The majority of solar panel systems are installed at the angle that maximizes sunlight exposure for that location. For most homeowners, the ideal solar panel installation angle is close or equal to the latitude of your home (on a south-facing rooftop) between 30 degrees and 45 degrees. When you tilt your solar panels to the same angle as your home’s latitude, you ensure the maximum average output from your system all year round.
- Existing Roof Design
While it would be ideal if every roof was angled the exact same as their home’s latitude, every property is unique and there’s no universal panel placement map. Most roofs have slopes between 30 and 40 degrees, which allows solar panels to lie flush against the rooftop and produce enough energy to power your home.For homes with a steep roof, you might not be able to place panels at the optimal tilt with traditional solar racking systems. If the steep angle is higher than the optimal angle for production, your best option is to lay your panels flat against the roof.Low-angle roofs also face obstacles during installation and can require specialized racking if you want to tilt them at the optimal angle. When you place solar panels flush against these types of roofs, there’s less electricity production and reduced solar savings in the long run.When it comes to flat roofs, solar installers usually use racking systems that will mount your panels up at the optimal angle. This allows the panels to face the sun directly, but you could be limited to the size of your system.
When you tilt panels on a flat roof, this can lead to panels shading one another unless they’re spaced out and panel rows are staggered. This results in a limit to the number of solar panels you can install compared to how many you could install if they were flush against the surface.
If you’re not sure how many panels could fit on your home or if your roof is ideal for solar, here’s a great article to help you determine if you’re a good fit for solar.
- Time of Year
While solar panels still work well in the winter, you’ll usually see a dip in total energy production during bad winters if snow covers your panels and reduces the power output. Winters in the northern hemisphere see the sun low in relation to the horizon.You can counteract lower winter production by installing your solar panels at a steeper angle than your latitude (around 60 degrees is optimal). This sets your panels up to perform more efficiently during the winter months because they’ll face the sun more directly when it shines from a lower point in the sky. Moreover, when you install panels at lower angles, snow won’t easily slide off your panels, which leads to long-lasting snow cover and decreased energy production.You can also reduce seasonal production variations by adjusting your solar panel angles twice a year in the spring and fall. A solar panel system at a 40-degree latitude could actually see a notable energy boost of about 4%.For the best dates to adjust your solar panel tilt, mark your calendars for September 15 to adjust the winter angle and March 15 for the spring and summer angles.
Which Is More Important: Solar Panel Orientation or Angle?
While your solar panel angle is important, the biggest factor to determine your energy production is the direction your panels face. For the best results, solar panels should be aligned towards the south (since we live in the northern hemisphere) because the sun is always in the southern half of the sky. While panel installation is often necessary on the east and west sides to accommodate production needs, we do not recommend installing panels facing north, even if it means the best optimal tilt.
Common Questions About the Best Solar Panel Angle
Many factors are used to calculate your best solar panel angle and this can leave homeowners confused about their next best step. Here are a few frequently asked questions about solar panel angles and orientation:
How do you determine the best angle for solar panels?
Determining the most efficient angle for your solar panels will vary depending on where you live. The rule of thumb is that the more solar panels are angled to face as close to the sun as possible, the better. The best angle for most homeowners is close or equal to your home’s latitude (usually somewhere between 30 to 45 degrees).
What is the best direction for solar panels?
South is the best direction for solar panels to face. Since the sun always occupies the southern half of the sky in the northern hemisphere, direct sunlight exposure is more abundant. However, it’s not recommended to install your panels to face a substandard direction in order to get the best tilt possible.
Is it worth tilting your solar panels?
Yes, tilting your solar panels allows them to more efficiently collect energy to power your home. Tilting them close to the same angle as your home’s latitude also gets you the maximum output from your solar energy system all year long.
Should solar panels face east or west?
While east or west isn’t ideal for solar panel orientation, the panels in both scenarios are still able to capture the sunlight to generate solar energy and savings.
Do solar panels need to be south facing?
While solar panels don’t need to be south facing, you’ll maximize your energy output with a south-facing system. It’s also better for residents in the northern hemisphere to install panels that face south rather than east or west. Rooftops that are north-facing are the least ideal location for solar panels.
Regardless of your rooftop type, it’s best to have a professional solar representative review your home’s roof and recommend the best solar panel array based on efficiency, angle, orientation and production.
If you’re ready to find out how much you can save on your utility bill every month, contact us today for a free solar quote!