When businesses first choose to go green, adding solar panels is almost always the first decision to be made. After that, the big question is: do you want the panels mounted on the roof or on the ground? Each has its advantages and disadvantages, and the best answer is entirely personalised to the situation.
Getting to Know the Prospects of Your Property
Before diving into the technical aspects, take stock of what you have. Check how the roof of your building is structured and what land is available around your building. A commercial solar PV installation is not a cookie-cutter solution, as what works perfectly for a warehouse could be entirely wrong for a retail park.
The age and state of your roof is an issue that you might not think is that important, but it is. If your roof membrane is getting older, it’s probably not a great idea to mount several tons of solar equipment on top. Once it comes time for the roof to be replaced, you will go through the hassle of having to remove the entire system and re-install it. Ground-mounted systems completely avoid this problem.
When Rooftops Make Sense
In cities, land space is valuable. So for many businesses, rooftop installation is the best solar option. There is no need to sacrifice car parking for landscaping areas, and you’re using space that would otherwise just sit empty.
Rooftops are also the most secure solar option. After installation, solar panels are protected from vandalism and damage from vehicles and equipment. This is especially important for businesses with public access or in secure vulnerable areas.
From an administrative point of view. Rooftop solar faces less scrutiny. Authorities are used to solar panels on commercial buildings and there are unlikely to be objections from neighbors. This is especially true when the panels are out of sight from the street.
That being said, there are limitations with rooftop solar installations. The pitch, orientation, and structural capacity of your roof will dictate what is possible. This is especially important when determining solar performance. In the UK, south-facing roofs are ideal. East and west facing roofs can still be good. Flat roofs provide more flexibility, but also more complexity and added cost, as mounting frames can be angled to optimise performance.
The Ground-Mounted Alternative
Compared to rooftops, ground-mounted systems provide greater flexibility. The angle and orientation of the systems can be adjusted since the building facades do not need to be taken into account. This usually results in superior energy generation throughout the system’s lifetime.
Maintenance is also easier. There are no scaffolding or height access issues, since technicians can reach everything from the ground. Ground access makes routine cleaning, fault investigations, and repair work simpler and less costly.
A ground-mounted commercial solar PV installation also has greater scalability. Future expansion of the system is straightforward, since you can simply add additional panels to the solar array. With rooftop systems, you need to work within the limits of the roof.
The disadvantages? You are using space that may have other beneficial uses. This can be a significant opportunity cost for businesses situated in areas where every square metre of ground space is revenue generating, for example garden centers, car dealerships, and outdoor hospitality venues.
There may also be significant planning permission for ground-mounted systems, especially in green belt or conservation areas. The visibility of the panels to neighbours and people passing by can sometimes lead to objections.
Cost Factors
There is a common opinion that rooftop installations entail less cost and complication, but this is not true. Ground-mounted systems are larger and more complex, but rooftop installations also need structural surveys, possible roof reinforcement, and more complex insurance arrangements.
The cost of access for a commercial solar PV installation is also higher for rooftop installations. Everything needs to be lifted, and in case the building is in use, there’s also more health and safety considerations to take care of.
What Works for You?
Instead of saying which of the two choices is better, consider which is more right for your situation. Is there adequate roof space? Is there a building structure that can support the panels on the roof? Would ground-mounted panels hinder your day to day activities? What are your long-term plans for the property?
If you’re leasing the building, a commercial solar PV installation on the ground might be better, because it can be more easily moved when you relocate. Property owners might prefer the rooftop system because of the more permanent installation.
In the end, however, excellent investment returns are possible in either case. The panels installed generate the same amount of power whether they are mounted on a roof or the ground; what matters is the chosen site and what makes the best economic and practical sense for the solar PV installation on your business premises.