COMPACTFLAT GS is our high-rise PV mounting system for flat roofs, designed for green roofs and systems with bifacial modules. The design requires only a few components and no long rails. Thanks to its height, there is space beneath the modules for light, plant growth, and maintenance work—an area where low-profile mounting systems on green roofs reach their limits. The system has been wind tunnel tested and is CE marked.

The system is primarily designed for green flat roofs and for flat-roof installations with bifacial PV modules. For green roofs, the high mounting height creates space between the system and the vegetation layer. For bifacial modules, it improves the conditions so that the rear side of the modules can also capture reflected light. Whether the system is suitable for a specific roof also depends on the roof structure, load-bearing capacity, and site-specific loads.

The greater distance from the roof surface allows reflected light to reach the back of bifacial modules. The actual amount of additional yield depends, among other things, on the reflectivity of the roof surface and the specific system design.

A green roof requires light and regular care; the area beneath and between the modules must remain accessible for this purpose. This is precisely the goal of the COMPACTFLAT GS’s elevated mounting system: it keeps the space clear for vegetation as well as for care and maintenance work.

There are two versions. The GS15 orients the modules at a 15-degree angle toward the south and operates with a shading angle of over 20 degrees—the rows must be spaced accordingly. GS10 PLUS arranges the modules in an east-west direction at a 10-degree angle and requires no shading angle, allowing for a denser layout. Both variants can be ballasted with stones or gravel, anchored, or secured using a combination of methods. In short: GS15 for south-facing installations with wider row spacing; GS10 PLUS for a dense east-west layout.

Over solid ballast such as pavers, over gravel, over roof anchors, or over a combination of anchors and ballast. The specific option and amount of ballast required depend on the roof structure, load-bearing capacity, and wind and snow loads at the site; AEROTOOL calculates the required weight for each bracket.

Ballast trays accommodate additional ballast and distribute the load more evenly across the roof structure. They are the right choice for high wind loads, limited permissible point loads, and ballasting on gravel roofs. Roof anchors work in the opposite way, reducing the required total weight. When combined, the two form a hybrid solution—one that is also suitable for locations with seismic activity because it prevents the system from shifting during an earthquake. A suitable ballast retention bracket holds the stones in place within the trough and distributes them evenly.

The coefficient of friction measurement kit can be used directly on a flat roof to determine how well the substructure adheres to the existing surface. The kit includes a weight block and a tension spring scale. The value determined on site is incorporated into the planning of the securing system and helps tailor the required ballast to the actual roof surface, rather than relying solely on a standard assumed value.

Our COMPACTFLAT leaflet is available for preliminary selection, the intake form for project preparation, and the bid template for the request for proposals. There are two separate assembly instructions for installation: one for the south-facing GS15 model and one for the east-west-facing GS10 PLUS model; the instruction corresponding to the selected variant is the one to follow. In addition, there are instructions for measuring the coefficient of friction. The leaflet and intake form are also available in English; the leaflet is additionally available in Italian and Spanish. To submit an inquiry, please use the inquiry form or email office@aerocompact.com.