At Switch to Solar, we have several options for installing and mounting solar panel arrays at your home or business:
Roof-Mounted Solar Panel Arrays
Roofs are often the most convenient and appropriate location for your solar panel array. Roof mounting is a labor-intensive process that requires careful attention to the roof structure and the weather sealing of roof penetrations.
There are several common approaches to roof mounting:
Standoff Solar Panel Mounting
Standoff solar panel arrays are mounted above and parallel to a sloped roof’s surface and are secured by fasteners to its support structure. At least three inches are needed between the roof and the bottom of the solar panel frame to allow air to circulate around the solar panel.
Rack Mounting of Solar Panels
Rack-mounted solar panel arrays are used on flat roofs. We install the solar panels above the roof’s surface, tilted at a non-zero angle to the roof, and secure them with ballast, by fasteners to the roof support structure, or some combination of both.
The total energy production for a rack-mounted solar panel array is often higher than a standoff array of the same size because of optimized orientation and lower operating temperatures. Compared to standoff mounts, rack-mounted solar panel mounts also withstand higher structural loads. However, they require costlier mounting hardware and can be less attractive.
Rack arrays usually run cooler than other mounts and can reduce heat gain through roofs.
Integral Solar Panel Mounting
This type of solar panel installation replaces some of the conventional roofing with building-integrated solar panels. Currently available products include:
- Solar roof slates (similar to masonry)
- Standing seam metal roofing
- Solar roofing tiles (also called solar shingles)
Integral-mounted solar panel arrays are a significant architectural feature and can be aesthetically pleasing. However, integral solar panels are more costly to install and difficult to weather seal. Because there’s a risk of serious leakage, it is recommended that tested and proven designs be used.
Direct Solar Panel Mounting
Direct-mounted solar panel arrays are affixed directly to the roofing materials, leaving little air flow between the solar panel and the roof. Because of this mounting technique, the operating temperatures are much higher than for other mounting techniques. This results in poorer solar panel performance and earlier degradation.
Direct mounts may only be appropriate for thin-film solar panel installations that are not as sensitive to operating temperature.
Using Solar Panels as a Shade Structure
If roof mounting is not an option, solar panel arrays can be mounted as a shade structure such as a patio cover or deck shade trellis. This type of mount supports all sizes of solar energy systems.
The installation cost with a solar shade structure is similar to installing a standard patio cover, and can take up a partial area or whole roof. If the solar array is mounted at a steeper angle than a typical patio cover, additional structural enhancements may be necessary.
The weight of the solar panel array is three to five pounds per square foot, which is well within structural limits of most shade structures.
This solar panel installation option is often more costly than roof mounting, but provides shade and allows easier access to the array for maintenance.
Other issues to consider include:
- Solar panel wiring must be carefully concealed to keep the installation aesthetically pleasing.
- Vines cannot grow around the solar panel array.
Ground-Mounted Solar Panel Arrays
These solar panel configurations are mounted with racks, poles, or tracking stands and must be secured to the ground. All ground-mounted solar panel arrays run relatively cool due to good air flow over both the front and back of the solar panels. A lack of obstructions, such as fences or shrubbery, can improve cooling.
Pole Mounting of Solar Panels
A solar panel array can be mounted on a pole if it is comprised of a small number of photovoltaic modules, so they are generally best used for installations that require small amount of power such as outdoor lighting. The pole will typically need to be set in concrete in order to prevent overturning during windy conditions.
Tracker Stand Solar Panel Mounting
Tracking solar panel arrays can absorb more sunlight than stationary arrays, so their solar panels have a higher energy output. In some cases, the additional energy output offsets the added cost and complexity of the solar panel installation. There are active and passive trackers.
- Active trackers direct the solar panel array toward the sun by using electric motors and gear drives, and they may track on one or two axes. Sun-seeking sensors or a computer can be used to track the sun’s position, which determines the direction of the trackers.
- Passive trackers generally track on only one axis. They use a fluid, such as Freon, that vaporizes and expands in the sun, causing the tracker to move toward the sun as the weight of the Freon shifts from one side of the tracker to the other.
Trackers perform better than fixed-tilt arrays in the summer when the days are long. However, they are less beneficial in winter when days are shorter. They work well for water pumping because water demand is usually higher in summer than in winter.