We see solar panels most commonly on the roofs of homes and buildings and sometimes even as car canopies. But what about ground mounted solar panels? Why would someone choose to install solar on the ground rather than their roof and are they worth it?
When to consider a solar ground mount
Sufficient ground space
A solar ground mount requires a property with sufficient space to install a structure on the ground. Not every home is going to have the adequate ground space needed. The space needed for a solar ground mount can vary depending on system size, and whether the panels are arranged in landscape or portrait. To find the width of a solar ground mount is easy. A Panasonic EVERVOLT 400HK solar module for example is 71.7”x 40.” If the solar array is arranged in landscape, with a layout of 5 wide and 4 high for example, we can easily see the ground mount will be 358.5 inches or 29.875 feet wide (71.7” wide panel x 5).
Calculating the depth and height of the solar array on the other hand will require a little bit of trigonometry. We know the span of the solar array is 200 inches or 16.667 feet.
From there, we take the pitch of the ground mount, in this case we will say 33 degrees, and follow this equation to get the depth and height of the ground mount.
Formulas:
- Height (H): Hypotenuse×sin(θ)
- 16.667×sin(33∘)=9.08 feet
- Depth (D): D=Hypotenuse×cos(θ)
- 16.667×cos(33∘)=13.98 feet
With our math, we now have the footprint for our ground mount. The ground mount is 9.08 feet tall, 13.98 feet deep, and 29.875 wide for a total square footage of 417.65 square feet. The ground mount will also need a minimum of two feet of clearance in the front to avoid snow and grass, so it will be a total 11.08 feet tall.
This is a large area obviously, and beyond the footprint itself, there are also set backs to consider. Most townships will require a minimum 15 foot set back from bordering property as well as not allowing ground mounts in the front yard where they may be visible from the street. If we add 15 feet in the set back area around our ground mount, we need a total area of 1,345.35 square feet. If your yard has the square footage available, then a ground mount is possible on your property.
Roof limitations
Sometimes the available roof space is not sufficient to offset the energy usage of the home. If the goal of the homeowner is to offset 100% of their electricity demand with solar, then a ground mount can meet that goal. Other times, the roof will be shaded – impacting production and disqualifying the roof from solar energy. When the home’s roof areas are not suitable for solar, and there is adequate ground area, then a solar ground mount can be a solution that makes sense.
Pro of a solar ground mount
Increased production
A ground mounted solar array can be a superior energy producer when compared with roof mounted solar arrays. There are a few factors at play here in this increased production. First of all, the ground mount can be aligned perfectly 180 degrees south – the ideal azimuth for solar in the northern hemisphere. On the other hand, a roof won’t always be 180 degrees south and will often have multiple roof planes facing different directions. The closer a solar array can be to 180 degree true south, the more productive it can be.
The tilt of the ground mount can also be set to the ideal angle to further maximize the production. Same as with the direction the solar is facing, the tilt of the solar panels makes a big difference as well. An ideal solar tilt in the Northeast is generally between 30-45 degrees roughly aligning with the location’s latitude.
We can say ground mounts can produce more by being oriented perfectly, but the numbers speak for themselves when it comes down to it. If we compare an 8 kW ground mount that is perfectly orientated with the production of an 8 kW roof mount that is just slightly off, the difference in annual production is nearly 1,000 kWh per year.
| Roof Mounted Solar vs. Ground Mounted Solar Production | |||
|---|---|---|---|
| Type | Pitch | Azimth | Annual Production |
| Ground | 33 | 180 | 10,453 kWh |
| Roof | 18 | 120 | 9,488 kWh |
This increase in production can satisfy the home’s energy demand and also lead to a stronger return on investment with more SRECs being produced, a larger tax credit, and more utility costs being avoided.
Easy access
With a solar ground mount, most times, you can literally just reach out and touch it. And this can have benefits when it comes to cleaning, snow removal, and even for any needed service and maintenance.
Roof avoidance
A Public Service Solar roof mounted solar installation will come with a lifetime workmanship warranty ensuring your solar investment is protected. However, some homeowners may want to hold off on reroofing if their roof is already nearing its lifespan, or perhaps the home has a unique material like slate which can add to costs and make solar more difficult. In the situations where it is more preferable not to touch the roof, a ground mount can be a great solution.
Cons of a solar ground mount
The biggest disadvantage of a ground mount is their cost when compared to roof mounted solar arrays. A ground mount costs more because there is additional site work needed. Electricity produced by the ground mount must be sent to the main electrical meter through a trench. Not only is there the physical work of digging the trench, but there is the cost of the wire to run through the trench. A structure must be built to hold the panels, and there may even be additional site work like laying gravel and cleaning up the area with seeding and haying. Despite the increase in upfront costs, ground mounts often have a better return on investment than roof mounted systems due to their unique production benefits.
Types of ground mounts
There are four main types of ground-mounted solar installations. Fixed-tilt ground mounts, adjustable tilt ground mounts, pole mounts, and tracking systems. Public Service Solar exclusively installs fixed-tilt ground mounts because there are no moving parts which improves longevity, they are more economical, and the high wattage solar technology available today makes the benefits of tracking or adjustable tilting less necessary. Most ground mounts available from solar companies in the Northeast are going to be fixed-tilt ground mounts.
How are ground mounts built?
Before installing a ground mount, Public Service Solar will conduct a site survey to confirm there is adequate ground space available for an installation. Once the site is confirmed, the permitting and approval process will be initiated ensuring compliance with local zoning regulations.
The foundation for ground mounts were historically concrete footings, but overtime have evolved to hydraulically driven posts or ground screws.
Types of ground mount footings:
Concrete footings: Holes are dug either by machine or by hand and are filled with concrete and metal posts.
Ground screws: Large earth screws are drilled into the ground by machine for support.
Driven piles: Metal posts hammered deep into the ground by machine for support.
Public Service Solar installs ground mounts using ground screws, as they are well-suited for PA and NJ’s diverse soil conditions, including rocky terrain. They also allow for quick installation, often taking less than a day.
Mounting structure
Once the foundation of the ground mount is completed, the metal racking system is assembled and secured to the foundation. From there, the solar panels can be installed in a similar manner to installing on roof mounted solar rails.
Electrical work
A ground mount will have the same electrical setup as a roof mounted solar installation with micro inverters installed on the underside of each individual solar module. The back side of the ground mounted structure will have metal racking set up to hold the solar combiner box, monitoring gateway, and disconnect. From the ground mount itself, the solar power must be run through a wire buried through a trench back to the home’s main electrical panel.
Additional site work
As part of our ground mount installations, Public Service Solar takes extra steps to ensure a clean and long-lasting setup. We lay down a weed mat and gravel to prevent overgrowth and erosion, and we install netting on the back of the panels for added protection.
After trenching for electrical work, we carefully cover the trench and return once the ground has settled to add more fill dirt if needed. Finally, we plant grass seed in the disturbed areas leaving your property looking better than it ever did before.
Conclusion
A solar ground mount can be a great option for homeowners who have the space and want to maximize energy production. With optimal tilt and orientation, easy maintenance access, and the ability to bypass roof limitations, ground-mounted solar can offer long-term benefits. While they do come with higher upfront costs due to additional site work and trenching, they remain a viable choice for those looking to offset their electricity usage completely.
At Public Service Solar, we make the process seamless by handling everything from permitting and installation to additional site work. Best of all, you can finance your solar ground mount for no money down, achieve a strong ROI, and take advantage of all the same incentives as a roof-mounted system. Ready to see if a ground mount is right for your property? Contact Public Service Solar today for a free consultation!
