How Many Mounting Brackets Does A Solar Panel Need?

Solar panels need to be securely mounted to ensure optimal performance and longevity. Proper mounting keeps the panels steady and angled toward the sun to maximize solar energy production. It also protects them from wind, rain, snow load, and other environmental factors.

There are several considerations when choosing the right mounting system and hardware for solar panels. The number of mounting brackets needed depends on the panel’s size, weight, location, and type of roof or ground mounting. Regional building codes also dictate specific structural requirements.

In this article, we will explore the key factors in determining how many mounting brackets are ideal for solar panels in different situations. With the right setup, solar panel systems can function smoothly for decades.

Table of Contents

Weight Considerations

A key factor in determining the number of mounting brackets needed for a solar panel installation is the weight per square foot of the solar panels. On average, solar panels weigh around 2-4 pounds per square foot of panel surface area (Source 1). This can vary somewhat depending on the specific solar panel model and manufacturer. For example, high efficiency SunPower panels tend to be on the lighter end at around 3 pounds per square foot, while more basic polycrystalline panels may be over 4 pounds per square foot.

When calculating the number of mounting brackets, it’s important to consider the total solar array size and weight. A 6 kW system with 24 panels that are 65×39 inches (about 13 square feet) would have around 312 square feet of solar panels. At 3 pounds per square foot, the total solar array weight would be about 936 pounds. Properly distributing this weight across enough mounting brackets is crucial for structural integrity and wind resistance.

Wind Loading

Wind can apply significant pressure and uplift forces on solar panels, which must be accounted for in the mounting system design (Exact source: YouTube – https://www.youtube.com/watch?v=5OYZZD63XVo). The wind pressure depends on the panel’s surface area, height above ground, geography and local wind speeds. Typical wind pressure values range from 10 to 60 psf for ground-mounted systems. But wind pressures can exceed 100 psf or more in very windy locations or during storms (Exact source: Solar Panels Network – https://us.solarpanelsnetwork.com/blog/solar-panel-wind-load-calculation/).

The mounting system must resist the resulting uplift and lateral wind forces. Excessive uplift can lift panels off the mounts while lateral forces can stress the mounting bolts and hardware. Proper engineering is required to calculate the wind loads and design adequate anchoring and attachments.

Roof Attachment

Roof mounting is one of the two main options for mounting solar panels, with ground mounting being the other option. Roof mounting attaches the solar panels directly to the roof of a home or building using mounting hardware like rails and brackets. There are some key differences between roof mounting and ground mounting that are important to consider.

According to Unbound Solar, roof mounting is often simpler and cheaper than ground mounting since it doesn’t require excavation or concrete. Roof mounted systems are also closer to the electrical system of the building. However, roof mounting can be more difficult if the roof is complicated or needs repairs. Accessing the panels for maintenance can also be challenging on roof mounts.

In comparison, Paradise Solar Energy notes that ground mounting provides more flexibility in panel placement and orientation. Ground mounts don’t require roof penetrations, which preserves roof warranties. Ground mounts are also easier to access for cleaning and repairs. But they take up more space and the initial installation cost is usually higher.

When choosing between roof mounting and ground mounting, it’s important to consider the unique factors of your property, goals, and budget. Both can be great options for residential solar panel systems. The decision depends on whether space, roof condition, or upfront costs are more important.

Mounting Hardware

Solar panel mounting hardware is a critical component in any PV system installation. There are two main types of mounting hardware used:

Mounting brackets – Brackets provide the direct physical mounting interface between the solar panel frame and the mounting rails. They are attached on each corner of the solar panel frame. The most common types are made of either aluminum or galvanized steel.
Mounting rails – Rails provide the base structure to mount multiple solar panels in an array. Rails are secured to the roof or ground mounts. They are commonly made of aluminum but can also be galvanized steel. Rails include pre-drilled holes to bolt the mounting brackets to the desired position.

Choosing the optimal mounting hardware ensures the solar panels can withstand wind, snow, seismic activity and other forces over the system lifetime of 25+ years.

Mounting Layout

The layout and spacing of the mounting brackets is critical for properly securing solar panels and distributing the structural load. According to Quick Mount PV, the optimal bracket spacing is one bracket around every four feet. This means that for a standard 60-cell solar panel that is approximately 3.5 feet wide, you would need at least two brackets per panel – one on each end. The brackets should be aligned vertically so that they form columns. This allows the weight of the panels to be transferred directly down through the mounting rails and brackets into the roof structure.

Some key considerations for proper bracket spacing include:
– Following the module manufacturer’s specifications for allowable overhang

– Spacing brackets according to local wind and snow loading requirements
– Placing brackets at the optimal points to catch the panel frame
– Allowing some tolerance for thermal expansion
– Avoiding obstruction with the panel junction box or cables

The mounting rails should be spaced apart as above. For example, using a 1.6m high panel, the rails should be spaced approx. 0.8m apart and the panels mounted between these rails at the recommended spacing. Improper spacing can lead to excessive deflection, damage to panels, and even collapse under extreme weather conditions. Following the best practices for layout and spacing ensures the structural integrity and longevity of the solar array.

Number of Brackets

The number of mounting brackets needed for a solar panel depends on several factors like panel size, roof type, and wind/snow loads. As a general guideline, most solar panels require 4 mounting brackets – one on each corner. However, larger or heavier panels may require additional middle brackets for support.

For standard 60-cell panels that are around 3’x5′ in size, 4 brackets is usually sufficient. If installing 72-cell or back-contact panels that are larger in size, you may need 6 brackets or more. Heavier glass-on-glass bifacial panels also often require 6+ brackets.

In regions with heavy wind and snow loads, additional brackets are recommended to provide extra reinforcement. Flat roof mounts tend to require more brackets than pitched shingled roofs since they lack the additional uplift resistance. Ultimately, consult your panel manufacturer’s documentation for specific bracket requirements based on your solar panel model and geographic location.

Regional Differences

Building codes and regulations can vary significantly by region when it comes to solar panel mounting. According to Arka360, local building departments enforce construction codes and regulations through their permitting procedures, so installers must obtain any required permits. Regions like California and Georgia have specific requirements:

In California, the California Electrical Code (CEC) provides requirements for solar PV systems, which are detailed in CEC Section 690. This covers aspects like conductor ampacities, overcurrent protection, disconnects, wiring methods, and connections. Georgia has also adopted codes like the National Electrical Code (NEC), but counties and cities may amend these codes or have additional regulations. The state provides a guide for navigating NEC requirements for PV system installation.

Other regions have their own specific codes as well. Installers should research the latest local and state codes and permitting procedures for each new solar installation.

Specialized Mounts

In certain situations, using standard flush roof mounts may not be ideal for capturing maximum sunlight throughout the day and year. Specialized mounting systems can optimize solar panel orientation and improve energy production. Some common types of specialized mounts include:

Tilted Mounts: Tilted mounts angle solar panels to face more directly towards the sun’s arc across the sky. This can increase energy production, especially in the mornings and evenings when sunlight hits at an angle. Tilting solar panels typically provides a 5-15% boost in total annual energy output.

Tracked Mounts: Trackers actively move solar panels to follow the sun’s changing position throughout the day. Single-axis trackers rotate panels along one dimension, while dual-axis trackers move in two dimensions. Tracking mounts can improve energy production by 25-40% compared to fixed mounts. However, they add complexity and higher costs.

Custom Mounts: For irregularly shaped roofs, structures with limited space, or specific aesthetic preferences, custom mounting systems can be designed and fabricated. While more expensive, custom mounts maximize solar panel coverage in unique situations. They are sometimes used on vehicles and boats as well.

When increased energy production is a priority, tilting, tracking, and customized mounting systems are viable options despite their added complexity. The return on investment for such specialized mounts depends on the specific conditions and goals of each solar installation.

Conclusion

In summary, the number of mounting brackets needed for a solar panel installation depends on several factors including panel size, roof type, wind and snow loads, and building codes. Most residential systems use 4 mounting points per panel. However, larger commercial systems may require up to 8 mounting points for additional wind resistance. When determining the number of brackets, it’s important to consult your solar provider and local building codes, as requirements can vary by region.

Based on research, 4 mounting brackets per panel is recommended for most residential solar installations. This provides adequate strength to handle panel weight and wind loads in most regions, while still minimizing parts and installation time. For heavier panels or high-wind regions, using 6 mounting points may be preferable. Regardless of bracket number, proper attachment to roof rafters is critical, along with using corrosion-resistant mounting hardware designed specifically for solar applications.

In the end, working with an experienced solar installer is highly recommended when designing your mounting system. They can assess your specific roof and panels to determine the ideal bracket number and layout to safely secure your system for the long haul.