Is Ground Mounted Solar Cheaper?

Ground mounted solar panels, also known as ground arrays, are installed directly on the ground rather than on a rooftop. They can be mounted on poles, frames, or racks that are anchored into the ground or ballasted with concrete blocks or gravel. Rooftop solar panels, on the other hand, are mounted on racks attached to the roof of a home, commercial building, or other structure.

Both ground and rooftop systems generate clean electricity from sunlight, feeding excess energy back to the grid for credit through net metering programs. However, there are some key differences between these two solar installation methods that impact costs and other factors.

Upfront Costs

Comparing upfront costs, ground mounted solar systems are generally less expensive per watt than roof mounted solar systems. This is primarily due to several factors:

With ground mounted solar, there are fewer limits on system size, allowing for larger economies of scale. Larger system sizes spread fixed costs like inverters and labor over more watts, reducing the cost per watt. Roof mounted systems are limited by available roof space.

Installing solar on the ground also avoids roofing labor and materials costs. Roof mounted systems require additional mounting, racking, and sealing hardware to integrate with the roof and maintain waterproofing.

Ground mounting utilizes simpler racking systems as the ideal tilt angle can be chosen and the ground provides stability. Roof mounted systems may need complex tilt legs or ballasted racking solutions to achieve the optimal tilt on varying rooftops.

Overall, by avoiding rooftop complications and leveraging economies of scale, ground mount solar installations realize material and labor savings that reduce average upfront costs per watt.

Ongoing Costs

The ongoing costs for ground-mounted solar tend to be higher than rooftop solar. A key reason for this is that ground-mounted systems require land leases or property tax payments since the arrays take up usable land. Rooftop systems avoid this added cost since they utilize existing roof space that typically goes unused. Land lease rates for ground-mounted solar average around $500 per acre annually but can vary widely based on factors like demand and location. Property taxes also must be paid on the land used for the ground array, which increases operational expenses. While rooftop systems may incur higher maintenance costs for access, they avoid land costs entirely. Overall, the annual land obligations associated with ground-mounted solar result in higher recurring costs compared to rooftop.

Efficiency

Ground mounted solar systems have the potential to be more efficient than rooftop systems because of their flexibility for optimal tilt angle and orientation. With ground mounted solar, the panels can be mounted on tilt structures that are angled to maximize sun exposure throughout the year. The ideal tilt angle depends on your location, but is typically equal to your latitude for maximum annual energy production.

In contrast, rooftop solar is limited by the existing roof angle and orientation. If a roof does not face south or is not tilted at the optimal angle, the panels may not receive as much direct sunlight. This can reduce energy production by 10-25% compared to an optimally tilted ground mount system.

Overall, ground mounting provides more flexibility to adjust the panel positioning as needed for maximum efficiency. This can result in greater solar energy production over the lifetime of the system.

Permitting & Zoning

When it comes to permitting and zoning, rooftop solar often has an advantage over ground-mounted systems. Rooftop solar usually only requires a simple building permit from the local jurisdiction, which is typically easy to obtain. The roof is already zoned for structures, so there are rarely any land use issues.

With ground-mounted solar, the permitting and zoning process can be more complex. Many residential properties are not zoned for utility installations, so a variance or zoning change may be required. The permitting process is also more extensive, often requiring site plans, geotechnical studies, and approval from multiple agencies. There is more discretion involved for local officials to impose requirements or reject the project.

For larger ground-mounted solar farms, the zoning and permitting process can be lengthy, complex and unpredictable. Rural agricultural land often needs to be rezoned which brings community concerns over land use. Permits are required from multiple entities like the town, county, wetlands boards, etc. Overall, rooftop solar enjoys an advantage in most cases when it comes to permitting and zoning issues.

Installation Speed

One advantage of ground mounted solar panels is that installation is generally faster and easier compared to rooftop systems. Installers have direct access to the ground which allows them to transport and maneuver equipment and materials more efficiently. There is no need to lift heavy panels and parts onto rooftops or maneuver them through homes and other buildings. With ground mounts, crews can also take advantage of larger equipment like cranes to hoist structures into place quickly. The open ground allows more flexibility in layout as well. This quicker and easier installation often translates into cost savings in labor for the overall project. Rooftop solar may require multiple days or weeks depending on accessibility, while ground systems can potentially be installed in 1-2 days. This faster deployment gets the system up and running sooner, allowing it to start producing energy and returns.

Maintenance

Maintenance is an important ongoing cost factor when considering rooftop vs ground solar installations. With rooftop systems, panels may be difficult to access for cleaning and repairs. The roof surface itself may be fragile or prone to leaking. Accessing rooftop panels generally requires specialized equipment like boom lifts or scaffolding. Technicians must exercise caution when working on angled rooftop surfaces as well.

In contrast, ground-mounted systems allow much easier, safer access for maintenance and repairs. Panels are mounted at chest height or lower, providing easy access without any specialized equipment needed. The ground surface is stable and free of height or fall risks. Panels can be cleaned and maintained more frequently and thoroughly since access is easier. Overall, maintenance of ground solar systems tends to be faster, safer, and cheaper than rooftop installs.

Security

Ground mounted solar panels can be more prone to theft and vandalism compared to roof mounted systems. Since ground mount systems are installed outdoors and often in remote areas, they are more easily accessed by potential thieves. Panels and wiring located on the ground are more vulnerable and present an enticing target.

Roof mounted systems typically have an extra layer of security simply by being elevated and out of direct reach. Accessing a roof mounted system usually requires climbing onto the roof, which acts as a deterrent. Ground mounted systems have no such obstacles for someone looking to steal components.

There are ways to enhance security for ground mount solar arrays, such as installing surveillance cameras, motion sensor lighting, and fencing around the perimeter. However, these add to the overall cost. Roof systems essentially have built-in security being located on top of the building itself.

When deciding between ground or roof mount, carefully consider the risk of theft based on the area and remoteness of the location. In general, roof mounted solar panels see fewer cases of theft and vandalism.

Aesthetics

When it comes to visual appeal, rooftop solar panels often look better than ground-mounted arrays. Solar panels on a roof blend in more naturally to a home’s architecture and are less conspicuous.

In contrast, ground-mounted systems stand out prominently. A large solar array covering the ground can seem industrial and disrupt the landscape. This is especially true in neighborhoods with tidy green lawns.

Rooftop solar preserves the aesthetics and character of the surrounding environment. For many homeowners, this visual factor makes rooftop their preferred choice over ground installations. With rooftop panels, you generate energy without drastically altering the appearance of your home or property.

Conclusion

When comparing ground-mounted and rooftop solar panels, there are pros and cons to each option. Ground-mounted systems often have lower upfront costs and can be easier to install and maintain. They also tend to be more efficient as they can be tilted at an optimal angle. However, they require more land and permitting can be more complex. Rooftop systems avoid land use issues but may cost more upfront and can be limited by the orientation of the roof.

Overall, for larger systems, ground-mounted solar is often the more affordable choice. The efficiency and ease of installation and maintenance make up for increased soft costs like permitting. However, for residential systems, rooftop panels may make more sense if roof space is available. The decision depends largely on your specific property and goals. Weigh the long-term cost savings and production against the upfront expenses to determine which option is right for your solar project.