Getting the most from flat-roof PV mounting
While solar panels are most commonly mounted on pitched roofs, many commercial buildings have flat roofs. And different roof types require different mounting systems to keep the panels secure and ensure optimal yield.
Flat roofs are notoriously less ideal for solar than pitched roofs if you do not have the right mounting equipment. If panels are installed directly onto a flat roof, they will not be inclined at the correct angle to harness the most sunlight and will be unable to self-clean when it rains. As such, flat-roof PV systems must have structures in place that angle the panels optimally to maximise yield.
But how else can you adjust your flat-roof PV array for the best performance? And which mounting equipment do we recommend for your flat-roof installations?
Optimising your system
Despite their poor reputation, installing solar panels on a flat roof has several advantages. For example, they often provide easier access for installation and maintenance than pitched roofs — meaning labour costs are low and maintenance is little hassle. What’s more, the panels will be less visible from the street if you have any aesthetic concerns.
However, to get the most energy from your flat-roof installation, users will need to install as many panels as possible on the roof space and be specific with the panels’ angle and orientation.
Ensuring you have the right angle of inclination is paramount to allow the panels to capture as much sunlight as possible. Generally, a minimum tilt of 10° is recommended for solar panels. Anything less than will require more maintenance and a potentially lower yield. Of course, in South Africa, panels should be installed facing north to make the most of the day’s sunlight. Choosing the right angle will minimise dirt build-up, panel shading and maintenance.
Precision engineering for flat-roof solar
Renusol: a German-based manufacturer of high-quality, no-nonsense PV mounting products. The company ethos of ‘Simple. Solid. Service’. is evidenced throughout Renusol’s offering. Its products are easy to install and built to last, and installers can design a complete solar mounting system online using the free PV-Configurator 3.0 tool. This software ensures accurate mounting system design every time and includes full documentation of parameters and a parts list.
Renusol offers a handful of flat-roof mounting systems that are perfect for South Africa’s solar market. High winds are often a risk for flat-roof systems, but all of Renusol’s solutions have been tested rigorously in wind tunnels to guarantee their safety and structural stability.
The Renusol FS is designed for flat roofs only. The Renusol FS is ideal for larger flat roofs with a limited load capacity thanks to its rail system and aerodynamic optimisation. The system is fixed onto the roof with a ballast rather than screwed into the roof itself. However, this option is available should a ballast be unsuitable.
The FS comes in a variety of options, including:
- East-west configuration
- South-facing 10°
- South-facing 18°
- High snow load
- Combination with MS+ for corrugated roofs
- FS with roof fixation rather than ballasts
- Cost-effective solution without streamliners
An east-west configuration is optimal when installing on a flat roof as it allows for most panels to be mounted on the roof, and the panels can still be self-cleaning. There is also a negligible amount of intra-row shading to maximise yield, and it offers slightly more energy absorption at the start and end of the day.
The FS is quick and simple to install as it features plug bolts instead of screws. It also comes with fewer parts and shorter rails for straightforward logistics, plus an optimised ballast that is lightweight but still keeps the panels securely in place. It also ensures no ‘creeping’ with heat expansion, thanks to the short rails.
We are also excited to introduce our new FS XL solution! As PV modules are getting bigger by the year, we needed to upgrade our iconic flat-roof mounting system to accommodate these larger panels. With our new FS10-EW XL and FS10-S XL systems, we can fit module widths between 1053–1168mm and 990–1065mm respectively. We have added new base rails, streamliners, eave support and ridge support — all of which you can find integrated in the PV-Configurator 3.0.
Applicable for ground-mounted and flat-roof systems, the Renusol ConSole+ is freestanding and ballasted, meaning it can be oriented in any configuration. This solution offers an unadjustable module tilt of 15° and does not require roof penetration. This system’s ‘plug-and-play’ design means it is exceptionally quick and easy to install: simply place the ConSole+ tray in position, fill it with the ballast and screw on the solar module.
And finally, the TriSole+. This mounting solution is a flexible, elevated system that allows for virtually unlimited possibilities. The system’s triangular module support is foldable and offers a mounting angle of 10°–35° that can be adjusted in steps of 5°.
The TriSole+ can be fixed into wood or steel/wood substructures, as well as standing seam clamps, corrugated roofs or foil roofs using the Nicolson Rooftrak®.