Roof mounting system and the ground mounting system are the two main methods to mount your solar panels.
Both systems have their pros and cons. We cannot say one is better than the other.
But many factors decide what system is best for you such as: your budget, available space, roof condition, required permission, etc.
What is a roof-mounted solar system?
Roof-mounted solar systems are very popular in city areas because they do not need extra space to install. These solar panels are installed on the roof using a mounting system.
What is a ground-mounted solar system?
A ground-mounted solar system is mounted on the ground. This occupies a large amount of land. This mounting system is suitable for large properties.
What you should consider when selecting a mounting method?
- The initial cost you like to make.
- Your preference.
- Size of your solar panel array.
- How large your land is? Soil condition?
- Your roof material, size, condition, direction, and pitch.
- Room for later alterations/ expansions (only if you need).
Instances, when the ground-mounted solar system is best for you
- When your roof is not strong enough or needs replacement.
- When your roof is not in the correct direction or does not have the required pitch.
- When your roof does not have enough space.
Instances, when the roof-mounted solar system is best for you
- When you do not have a large property.
- When sunlight is obstructed by trees and many other objects and does not reach the ground level.
- When the soil of your land is not good to build the foundation to mount your solar panels.
Let’s get to know more details about these two systems under few topics.
Ground solar systems cost you more compared to the roof solar system.
The reason is, when you install a solar panel on the roof you already have the foundation or the surface to fix all these mounting systems and solar panels.
But for a ground solar system, you have to specifically build a foundation. Otherwise, you cannot fix the solar panels to the ground.
This costs you more as you need more materials and labor to build this foundation and fix the mounting device and panels onto it.
But if roof replacement is required to install solar panels and you have enough land, then the ground solar system is best for you.
Reason – most of the time roof placement needs more money than the initial cost for ground solar systems.
When mounting a solar system, the user’s preference must be taken into account. This is a huge investment and something that will be on your property for about 20 – 25 years. So this structure should not be a burden for you.
Some do not like to build structures like this on the ground and reduce their free land. For them installing panels on the roof is a good option.
Also, many do not prefer the roof mounting method as they think it can harm their roof or do not like the look of the roof after installing panels. So the ground-mounted panels are a good option if they have enough land.
Some think that ground-mounted solar panels are not suitable or aesthetic enough to have a good landscape. So for them, there are aesthetically pleasing ground mounting racks and poles available in the market.
Effects on solar panel installation and later alterations;
Solar panels’ direction and mounting angle.
Even though ground mount solar panel cost you more it gives you the flexibility of installing solar panel in the optimum direction and at the optimum angle.
Installing solar panels on the roof does not give this flexibility. Your solar panel direction and the mounting angle all depend on your roof direction and the pitch.
Most of the time it hard to fix the roof solar panel in the optimum direction and at the optimum angle if the roofs are not pre-planned to install solar panels.
Size and weight of the solar panels
The size of the solar panel array that you can put on either the roof or the ground is limited by the available space.
If you have a large free land and you need to install a large solar panel array then it is better to install on the ground as it gives you more space.
Installing solar panels on the roof is limited not just by the size but the roof weight capacity as well.
The weight capacity of the roof is the amount of load that roof can withstand. This usually decreases with the age of your roof. When you install the panels on the ground, the panels’ weight will not be a matter.
If you plan to add solar panels later on it is better to install the solar panels on the ground if you have more ground space. Because the roof has limited space and weight capacity, it will not able to hold more extra solar panels.
So you will not be able to do many alterations later if you install the panels of the roof. But if you install the panels on the ground then it gives you more room for later alterations.
Foundation/ mounting surface
When installing the solar panels on the roof you have to make sure that the roof can withstand the panels’ weight. Also, the roof has to be in good condition and it has to be built from suitable quality materials such as shingle roofs, metal roofs, tiled roofs, etc.
When installing solar panels on the ground you have to be especially careful about the soil. When mounting solar panels on the ground you have to fix the mounting rack to the ground first. So for that, you have to dig the ground and build the foundation layer.
If your soil is hard and filled with rocks then it will be difficult to dig. So your land should have proper soil to build a good foundation.
As a special foundation is built for ground-mounted solar panels, you can make sure that the foundation is designed to hold the panels for a prolonged period. The reason is, solar panels have about 20 – 25 years of a lifetime.
But roof-mounted solar panels do not get this advantage. So you have to repair the roof from time to time. This costs you more as you have to remove and reinstall panels, every time you have to repair the roofs.
Most times to install roof solar panels you do not need any special permission. There some instances like installing solar panels on flat roofs.
But when it comes to the ground-mounted solar panels you have to get permission most of the time. This is because you have to build the mounting structure/ solar panel racking as a separate structure.
This can be an exhausting and time-consuming process. Also, this costs you more as you have to pay the permitting fees.
Ground-mounted solar systems are more accessible when compared to roof-mounted solar systems.
So ground-mounted solar systems are easy to reach for installation and maintenance works. But roof-mounted solar systems are not easy to reach. Workers need special gear and must take safety precautions to work on the roof.
Solar systems mostly do not need much cleaning as they are designed to be self-cleaned by rain. But if you are living in an area with less rain then you have to clean the panels to have a good output.
Also, you have to clean the snow, leaves, and other debris collected on the panels.
As ground-mounted solar systems are easy to access, you can even clean and check up the panels on your own.
But as roof solar systems are harder to access it is hard to clean them or troubleshoot them on your own. So if you are not competent it is better to hire people to maintain the panels.
Also, when it comes to roof-mounted solar systems you have to examine your roof from time to time. There can be undetected leakages and cracks on the roof. Sometimes solar panels installing process can result in these cracks and leakages if the workers are not careful enough.
These cracks and leakages will worsen with time. This weakens the roof and ultimately roof will collapse.
A big disadvantage of roof-mounted solar panels is usually roofs do not have a long life as a solar panel. So you have to repair the roof from time to time to keep the roof strong enough.
When repairing the roof you have to remove the solar panels and reinstall them. This will cost you more.
So as you can see when comparing the maintenance costs roof-mounted systems cost more than ground-mounted systems.
The efficiency of solar panel
Solar panel efficiency depends on many factors. When it comes to the roof solar panels and ground solar panels solar panel efficiency differs between these two methods mainly due to the following factors.
- Sunlight intensity/ shading
Most of the time there is a chance that ground-mounted solar panels are shaded from overhead structures such as tall trees. When it comes to the roof-mounted solar systems the chance of them getting shaded is less as they are at a higher level.
So the sunlight intensity that reaches the solar panels can be higher for roof solar if we consider this aspect only. But this is not the only factor that affects the incident sunlight intensity.
- Direction and angle
Installing the solar panels in the optimum direction and at the optimum angle helps to receive a good amount of sunlight.
When it comes to the ground solar panels you get the freedom of installing the solar panel in the optimum direction and at an optimum angle.
But when installing panels on the roof you do not get this freedom. You have to consider the roof direction and the pitch.
- Surface temperature
Unlike roof-mounted solar panels, ground-mounted solar panels cool off pretty quickly. So the surface temperature of the ground-mounted solar panel remains lesser than the roof-mounted solar panel.
When surface temperature is high it decreases the efficiency of the panels. So the ground solar panels generate high output voltage than roof solar panels.
When solar panels are at a higher altitude they become closer to the sun. So the incident sunlight intensity increases.
Roof-mounted solar panels are at a higher altitude than ground solar panels. So they receive more sunlight which increases the output of the solar panels.
As you can see many factors affect the output of the solar panel. Some factors affect positively the ground-mounted solar panels and others affect positively the roof-mounted solar panels.
So when selecting a mounting system you have to consider every factor and select the best mounting system for you.
You can check our article,”12 Factors That Affect Output of Solar Panels” to know more about factors that affect the output of your solar panels.
When we compared the ground-mounted solar panels and the roof-mounted solar panels we can see that the ground-mounted solar panels are safer.
Ground-mounted solar panels are easier to access. Workers do not need any special gears to reach the panels.
Roof-mounted solar panels are harder to access. Also, it will be really dangerous if someone with less experience tries to work with these panels as they can seriously be injured by falling off the roof.
It is not the only problem. If the solar panel installation was done with less care that can result in leakages and cracks. If these cracks and leakages are undetected for a long period of life then the roof can collapse and results in very serious injuries to the residents.
|Initial cost less||Initial cost high – installation needs more manpower and more parts|
|No need for extra land/ space – good for city area||Need extra land|
|Easy permitting process||Permitting process is complex and expensive|
|Higher altitude||Lesser altitude|
|Access is hard – installation, cleaning, maintenance need competent workers with special gear||Easy access|
|Maintenance cost is high||Maintenance cost is less|
|The surface temperature of panels are high||Cooler panel temperatures|
|Installation affected by roof orientation and pitch. So these factors should be considered.||Installation planning is easier.|
|Less room for later alterations||More room for later alterations|