Mounting systems represent one of the most significant opportunities for improvement in the solar industry. Mounting systems are an essential component of solar arrays because they are responsible for securing solar panels to the ground or the roof of a building. Despite the fact that the market for solar mounting systems is likely the most competitive of all solar product markets, mounting systems are still just a drop in the bucket. In this article, we will go over the fundamental categories of roof-mounted solar systems to assist new installers in getting a better understanding of the installation process.
Mounting solar panels on sloped roofs
Solar panels are typically mounted on the sloped roofs of residential buildings that have chosen to install solar energy systems. There are a variety of mounting system options available for angled roofs, the most common of which are railed, rail-less, and shared rail mounting systems. All methods involve penetrating or anchoring into the roof in some way, whether it be by attaching to the rafters or to the decking directly.
The rows of solar panels that make up the standard residential installation are held up by rails that are affixed to the roof. Clamps are used to attach each panel, which is typically arranged in a vertical or portrait orientation, to the two rails. Flashing is installed around and over the hole in the roof to create a watertight seal. The rails are fastened to the roof using some kind of bolt or screw.
- Railless Mounts
It should not be necessary to explain how rail-less systems work; rather than being attached to rails, solar panels in these systems are attached directly to the hardware that is connected to the bolts or screws that are going into the roof. The rail can be thought of as being equivalent to the module’s frame. Rail-less systems still require the same number of attachments into the roof as railed systems do; however, by removing the rails, manufacturing and shipping costs are reduced, and the installation process is sped up because there are fewer components. In a system that does not make use of rigid rails, the panels’ ability to be positioned in any orientation is not constrained by the direction of the rails.
- Shared rail system
Shared-rail systems take two rows of solar panels, which would normally be attached to four rails, remove one of the rails, and then clamp the two rows of panels to a middle rail that they both share. Because an entire length of rail, or more than that, is removed in shared-rail systems, the number of roof penetrations that are required is reduced. Panels can be positioned in any orientation, and the installation process is incredibly quick once the accurate positioning of the rails has been determined.
Ballasted and non-penetrating mounting systems are gaining traction nowadays, despite the fact that mounting them on sloped roofs was once thought to be impossible. These systems are basically draped over the peak of a roof, which allows the weight of the system to be distributed evenly on both sides of the roof.
The array is kept in a nearly suctioned-like state to the roof by strain-based loading. There is a possibility that the system will still require ballast, which is typically composed of small concrete pavers. This additional weight is positioned on top of load-bearing walls. Because there will be no penetrations, the installation should go very quickly.
Mounting solar panels on flat roofs
Large flat rooftops are a common location for the installation of commercial and industrial solar applications. Examples of these include the roofs of big-box stores and manufacturing plants. These roofs might still have a very slight pitch, but it won’t be nearly as steep as residential roofs that slope in one direction. Solar panel attachment systems for flat roofs are typically ballasted and require only a small number of penetrations.
Flat roof mounting systems are able to benefit from pre-assembly because they are positioned on a large, level surface. This makes the installation process for these systems relatively simple. The majority of ballasted mounting systems for flat roofs make use of something called a “foot” as the base assembly. This is a basket- or tray-like piece of hardware with a tilted design that sits on top of the roof and holds ballast blocks in the bottom while also holding panels along its top and bottom edges. Typically, a tilt of between 5 and 15 degrees is applied to the panels in order to maximize the amount of sunlight they absorb. The load limit of a roof will determine how much ballast is required for the structure. When a roof is unable to support a significant amount of additional weight, it may be necessary to install some penetrations. Clamps or clips are used to secure panel assemblies to their respective mounting systems.
When possible, solar panels should be oriented so that they face south on large flat roofs; however, if this cannot be accomplished, solar panels can still be arranged so that they face east to west. A number of companies that manufacture mounting systems for flat roofs also produce east-west or dual-tilt systems. The only difference between the installation of east-west systems and south-facing ballasted roof mounts is that east-west systems are rotated by ninety degrees and the panels are butted up to one another, giving the system a dual-tilt. Because there is less space between rows, a greater number of modules can be installed on a roof.
Mounting systems for flat roofs can take on a number of different forms. In spite of the fact that aluminum and stainless steel systems are still used on flat roofs, many plastic and polymer-based systems are becoming increasingly popular. Installation is facilitated by their low weight and the fact that their designs can be molded.
The best way to determine which solar panel mount system will work best for your roof is to consult with licensed installers who have experience in the field. If you do research on different mount brands and have a preference, you and the solar installer can talk about the different options available to you.