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What are the different types of solar roof mounting systems?

What are the different types of solar roof mounting systems?

One of the biggest areas of innovation within solar energy involves the  mounting system . Probably the most competitive solar product mounting systems on the market are an important element of solar panels – they secure the solar panels to the roof or ground.

What are the different types of solar roof mounting systems?

Here, we review the basic categories of roof-mounted solar systems to help new installers understand installation. We explore the different ground-mounted systems (including garages and tracking systems) in another must-read article.

Pitched ceiling mounting systems

When it comes to residential solar installations , solar panels are often found on sloped rooftops. There are many mounting system options for these angled roofs, with the most common being rail, railless, and shared. All of these systems require some type of roof penetration or anchorage, either attached to the joists or directly to the deck.

The standard residential system uses rails attached to the roof to support rows of solar panels. Each panel, usually laid upright/vertical style, is attached to two rails with clamps. The rails are secured to the roof by a bolt or screw type, with flashing installed around/over the hole for a tight seal.

Trackless systems are pretty self-explanatory: instead of being attached to the rails, the solar panels attach directly to hardware attached to studs/screws going into the roof. The module frame is essentially considered the rail. Trackless systems still require the same number of ceiling fixtures as a tracked system, but removing the tracks reduces manufacturing and shipping costs, and having fewer components speeds up installation time. The panels are not limited to the direction of the rigid rails and can be placed in any orientation with a railless system.

Shared rail systems take two rows of solar panels normally attached to four rails and pull out one rail, clamping the two rows of panels onto a central shared rail. Fewer roof penetrations are needed in shared rail systems since an entire length of rail (or more) is eliminated. The panels can be placed in any orientation, and once the precise positioning of the rails is determined, installation is quick.

Once thought impossible on sloped roofs, ballasted and non-penetrating mounting systems are gaining traction. These systems are essentially draped over the roof of a roof, distributing the weight of the system to both sides of the roof.

Strain based loading keeps the array nearly sucked to the ceiling. Ballast (usually small concrete pavers) may still be needed to hold the system down, and that extra weight is placed on load-bearing walls above the stops. Without penetrations, installation can be incredibly fast.

Flat roof mounting systems

Commercial and industrial solar applications are often found on large flat roofs, such as large retail stores or manufacturing plants. These roofs may still have a slight slope, but not as much as sloped residential roofs. Solar mounting systems for flat roofs are usually ballasted with few penetrations.

Flat roof mounting systemsSince they are placed on a large, level surface,  flat roof mounting systemsthey can be installed relatively easily and benefit from pre-assembly. Most ballasted mounting systems for flat roofs use a “foot” as the base assembly: a basket or tray-like piece of hardware with a sloped design that sits on top of the roof, supporting blocks of concrete. ballast at the bottom and panels along its top and bottom edges. The panels are tilted at the best angle to capture the most sunlight, usually between 5 and 15°.

The amount of ballast required depends on the load limit of the roof. When a roof cannot support much extra weight, some penetrations may be necessary. The panels are attached to the mounting systems using clamps or clips.

On large flat roofs, the panels are best positioned to face south, but when that’s not possible, solar power can still be generated in east-west configurations. Many manufacturers of flat roof mounting systems also have east-west or dual-tilt systems. East-West systems are installed just like south-facing ballasted roof mounts, except the systems are rotated 90° and the panels are butted together, giving the system a dual pitch. More modules fit on a roof as there is less space between rows.

Flat roof mount systems come in a variety of makeups. While aluminum and stainless steel systems still have a home on flat roofs, many plastic and polymer-based systems are popular. Their lightweight, conformable designs make installation quick and easy.

Solar roof tiles and BIPV

As the general public becomes more interested in aesthetics and unique solar installations, solar shingles will only increase in popularity. Solar shingles are part of the building-integrated PV (BIPV) family, which means that solar energy is built into the structure. No mounting systems are needed for these solar products because the product integrates with the roof and becomes part of the roof structure.