When you decide to install solar panels, you’re not just investing in clean energy—you’re also making a long-term investment in your home. That’s why professional installers take a lot of time designing the system and determining exactly where and how the panels should be placed on your roof. The panels’ placement impacts everything from the efficiency of your system to the panels’ lifespan. Keep reading to learn how solar professionals analyze your roof to decide on the best layout and angle for your solar array.

Step 1: Assessing the Roof

The first thing installers look at is the direction your roof faces, also called its orientation. In the northern hemisphere, south-facing roofs get the most sunlight throughout the year; in the southern hemisphere, it’s the north-facing slopes that get more sun time. East- and west-facing roofs can also work, but they typically get slightly less sun.

Beyond compass directions, installers also analyze the roof’s slope. A roof with a steep angle may limit the size of the solar array, while a flat or gently sloped roof may require racking systems to tilt the panels at the right angle. Additionally, the overall structural integrity of the roof needs to be looked at. Installers check for aging shingles, weak framing, or other issues that may need repair before solar panels can be mounted safely.

Step 2: Conducting a Shading Analysis

Shading is one of the biggest drains on solar panel efficiency. Even partial shading from trees, chimneys, or nearby buildings can cut down your production significantly. To account for this, installers perform a detailed shading analysis when they’re designing your system.

Solar-specific mapping tools or drone-based imaging help map out how shadows will move across your roof throughout the day and even in different seasons. These tools use GPS coordinates and sun path charts to simulate the sun’s angle, allowing installers to determine which roof sections receive consistent sunlight.

Step 3: Choosing the Right Tilt Angle

The angle your solar panels are mounted at is just as important as where they’re installed. The tilt affects how directly sunlight can hit the panel, influencing overall efficiency. Here are some things your installer will consider when deciding the perfect angle for your panels:

• Latitude Rule of Thumb: A common starting point is to set the tilt angle equal to the latitude of your location. For example, if you live at 35° latitude, panels tilted at about 35° will maximize energyproduction.
• Seasonal Adjustments: Some homeowners prioritize either summer or winter production. A slightly flatter angle may capture more summer sunlight, while a steeper angle is better for winter when the sun is lower in the sky. But keep in mind that most residential systems don’t have adjustable panels; if you want to prioritize one season’s production, it might mean setting your panels at an angle that slightly reduces production in a different season.
• Roof Pitch Considerations: On pitched roofs, the natural angle of the roof often dictates the panel angle. Installers may use special mounting systems to adjust the tilt if the roof slope is quite far from what you want it to be, but more often than not, using the natural roof angle is the most cost-effective choice.

Step 4: Local Climate and Weather

Installers also factor in your local climate and weather patterns when designing your system. In regions with heavy snow, for example, a steeper panel angle helps snow slide off more easily, preventing buildup that can block sunlight. On the other hand, in areas prone to high winds, installers ensure the panels can withstand gusts without impacting roof integrity. They may also opt for a slightly flatter angle to make the wind less likely to catch the underside of the panels.

Heat is another thing to keep in mind—solar panels are less efficient at higher temperatures. Installers may design the system to allow more airflow beneath the panels, which helps dispel the heat and reduce damage to the panels.

Step Five: Roof Space and Aesthetics

Even if your roof faces in exactly the right direction, practical space considerations can still impact the final panel placement. Vents, skylights, chimneys, and dormers can limit where panels will fit. Installers use design software to create a detailed digital map of your roof, then plot out exactly where each panel will go. This allows them to maximize space without interfering with any existing features on your roof.

Some homeowners also might prefer that panels be placed on less-visible sections of the roof to maintain curb appeal. While installers prioritize efficiency, they often work with homeowners to balance performance with appearance. In some cases, multiple roof planes can be used, even if one orientation isn’t perfect.

Step 6: Electrical Layouts

Placement is not just about sunlight—it’s also about wiring and electrical efficiency. Installers design the layout so that wires are as short as possible; this helps with minimizing energy loss and material costs. The inverter location, usually near the home’s main electrical panel, is also important to consider.

Precision + Planning = Maximum Efficiency

The placement and angle of solar panels are not guesswork—they’re the result of careful calculations, thorough analysis, and advanced modeling. From roof orientation and shading to tilt angle and even the length of your wires, installers weigh dozens of factors before finalizing a system design.

This ensures that your solar array produces as much clean energy as possible while remaining safe, durable, and visually acceptable. So, if you start to wonder why your system design is taking so long, you’ll now know exactly how much work goes into getting your Mission solar panels installed at exactly the right angle!