There are many types of solar mounts, but the three primary options for commercial solar arrays include rooftop, ground mount, and parking canopy locations.
Empty rooftop space is a great location to place solar panels and is often abundant in large commercial buildings and distribution centers. When evaluating for rooftop solar, it’s important to consider the age of the existing roof, geographical latitude, weather conditions, roof slope, and shading from adjacent buildings or vegetation. Melink uses a ballasted roof mount racking system, meaning that we typically do not make roof penetrations.
For commercial solar PV systems, there are generally three types of roof mounting options and the solution is dependent on the type of roof. In all cases, considerations must be made for the roof’s age, structural integrity, access to equipment, and necessary setbacks for fire and life safety requirements.
Roofs that are flat with a slope less than 7 degrees are commonly able to utilize a ballasted racking system. This ballasted roof mount system does not generally require roof penetrations and will add roughly 3-7 PSF of weight to the roof. In areas where the roof cannot structurally support this added weight, mechanical attachments can be used. With this type of system, the solar modules are typically installed with a pitch of 5, 10, and 15 degrees.
Installing solar on a standing seam roof typically results in the lowest installed cost per watt, as the racking system for a standing seam roof is the least expensive. The racking systems typically used for standing seam roofs do not penetrate the roof but rather use a special clamp that secures the solar array by attaching to the roof seam. Solar panels can either be mounted flush with the slope of the roof or installed at a higher pitch. The higher pitch increases production but can also increase cost and will require spacing between rows.
Installing solar on a pitched shingle roof generally requires the use of special flashing attachments to mechanically attach the solar array to the roof structure under the shingles. It is most common for solar modules to be mounted flush with the slope of the existing shingle roof.
A ground-mounted PV system is a solar array that is located on the ground with posts driven into the soil. This system is easy to place because they can be in open land. They require more racking than a roof-mounted system; however, they typically produce more energy because they can be installed with a more optical tilt angle. To capture the maximum amount of sunlight, ground-mounted solar systems use a metal frame connected to the earth to hold the panels at a fixed angle. Other ground-mounted systems may use pole mounts that can automatically tilt the solar panels to capture the optimal amount of sunshine, daily and seasonally. Types of ground mount systems include:
Fixed Tilt Systems
Fixed tilt systems are typically used for large projects and are comprised of either single-post or dual-post designs. Especially for large facilities, a fixed tilt system results in high cost savings in terms of assembly time due to a smaller number of posts needing to be placed. Different frame variants for different module arrangements also guarantee a cost-effective choice of materials optimized to the desired configuration.
Single Axis Tracker
A solar tracking system maximizes a system’s electricity production by moving panels to follow the sun throughout the day, which optimizes the angle that panels receive solar radiation. Solar trackers are typically used for ground-mounted solar panels and large, free-standing solar installations like solar trees. They are typically not used in most residential solar projects but have a place in the utility-scale and commercial/industrial solar market.
Dual Axis Tracker
A dual axis tracker allows panels to move on two axis, aligned both north-south and east-west. This type of system is designed to maximize panels’ solar energy collection throughout the year. It can track seasonal variations in the height of the sun, as well as the sun’s normal daily motion.
A solar PV canopy is an elevated structure that hoists solar panels in overhead locations such as parking lots or other paved areas. Cars can park beneath, taking advantage of the shaded area. Many solar canopies incorporate charging stations so that drivers of electric vehicles can recharge with solar power while parked. Because of their visibility and user-friendly parking experiences, solar canopies often bring education and awareness of solar energy to the public. In practice, solar canopies are similar to ground-mounted solar panels — each provides an alternative to rooftop solar, whether because a roof can’t host solar panels or because a property’s electricity needs are too large for a rooftop solar system.
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