Kinds of Solar Racking System
Author: Darvin Tocmo Date Posted:4 April 2018
Solar racking system is an extremely important part of installing a solar system. A solar racking system secures solar panels to your roof or to the ground, depending on the type of solar energy system being installed.
If you’re interested in adding solar panels to your home, you’ll need to know what a solar racking system is and what options exist.
In this article, we summarize the common mounting systems available and give you insights on where to use them.
Roof-Mount Racking Systems
The most common installation of residential solar panels is a roof-mount racking system. Within this category, you’ll find a few different types.
A rail-mounting rack system gets used on a roof sloped at an angle. You secure the rails to the roof using a bolt or screw with flashing installed either around or over the hole made by the bolt or screw to create a watertight seal preventing any leaks. Each solar panel is then attached to two rails, one on the top and one on the bottom.
Pros of the rail-mounting system:
- Solar panels are secure.
- This mounting system works well in areas with high winds.
Cons of the rail-mounting system:
- The pieces weigh more than a shared rail system and a rail-less system.
- The system requires penetrations into the roof.
- The arrangement is rigid for where you can install the panels.
Similar to a rail-mounting system, the shared-rail system uses rails. However, instead of two rows of rails for each row of solar panels, you only need three rows of rails for every two rows of panels. The two rows share the middle rail, which means fewer bolts or screws get installed on the roof.
Pros of the shared-rail system:
- The installation is faster and easier than a rail-mounting system.
- You can install the shared rails vertically or horizontally.
- This installation is compatible with both tile and composite roofs.
- The item uses fewer components than other rail systems and fewer penetrations than a rail-less system.
Cons of the shared-rail system:
- This system weighs more than a rail-less system.
- You’ll spend more on shipping costs than a rail-less system.
- Panel installation is not flexible.
Rail-less Mounting System
Another option on a sloped roof is a rail-less system. This system doesn’t require the solar panels to be attached to rails. Instead, the panels themselves get attached to the roof with bolts or screws.
Pros of the rail-less mounting system:
- You have more flexibility over how the solar panels get installed, including the direction.
- This system has lower costs because you don’t need to have the solar panels attached to the rails for shipping.
- The arrangement overall has fewer components, which speeds up installation time, making it faster than a rail system.
Cons of rail-less mounting systems:
- You have only a small part of the panel frame attached to the roof, which, over time, can cause damage from microfractures, resulting in a loss of output.
- This system has more penetrations than other racking systems.
Flat-roof mounting systems typically use this type of mount to keep the solar panels in place. However, you can use them on other roof types as well. You use weights to hold the solar panels in place.
Pros of ballasted-mount systems:
- You don’t need penetrations.
- The system costs less to install, and the overall installation is faster.
Cons of ballasted-mount systems:
- This system increases the load on your roof.
- You couldn’t use this system in areas with high winds.
- You’ll have more difficulties getting the weights up to your roof.
- Costs may be higher to ship the system because of the extra weight.
Ground-Mount Solar-Racking Systems
If you have a larger plot of land, you may be able to have a ground-mounting system instead of a roof-mounting system. Ground-racking systems typically cost the same as roof systems on a per-watt basis and can save you money in the long run if your rooftop isn’t ideal for solar panels, especially if your roof doesn’t face south or is not at the right angle. You’ll gain more flexibility over placing ground-mount systems, and you can adjust them to meet the energy consumption in your home.
Standard Ground Mounts
This type of solar-racking system uses metal frames driven into the ground. These frames hold the panels at a fixed angle, although some systems are manually adjusted up to three times a year so that you can shift them as the seasons and sun routes change.
Pros of standard ground mounts:
- These mounts don’t require penetrations into your roof.
- The mounts are lightweight and easy to move.
- Ground mounts are generally more productive than roof mounts because they’re set at the perfect angle.
- You can easily access ground mounts for cleaning and maintenance, such as removing snow in the winter.
Cons of standard ground mounts:
- You need open land to place the solar panels.
- You also must have a spot on the land where the panels can face the right angle with no interference from trees or other obstructions.
With the pole-mounted racking system, multiple solar panels get attached to a single pole. These poles become raised higher off the ground and often use a tracking system to tilt the panels automatically to make sure the panels absorb the most sunshine possible.
Pros of standard pole mounts:
- You don’t need to install these types of mounts on your roof.
- These mounts are more productive than most other systems because they use a tracking system and, since they’re higher up, they are able to avoid obstructions.
Cons of standard pole mounts:
- You need a sizeable area in which to place the poles away from obstructions.
- You need to install the poles so that they’re more secure and can’t be moved easily.
Racking and mounting solar panels may not be the flashiest part of installing solar, but it is one of the most important considerations to protect your system as well as your roof.