11 Jun

The Good, the Bad, and the Ideal: Roof, Ground or Lot Mounted Solar?

In the commercial solar industry there are three main sites to install a solar photovoltaic (PV) array: on the roof, on the ground, or on a (parking) lot. Each option has upsides and downsides. Every solar project is unique and what works for one company may not work for another. Let’s take a moment to discuss the pros and cons of each installation site so you may find the ideal location for your solar project.

roof_solar

A roof mount at the Orange County Convention Center in Florida.

ROOF

            The roof is possibly the most common site for a commercial solar array. It is great because it is right at the location where the electricity will be consumed. This also makes the soar array more affordable than in other locations for several reasons. The placement on the building means less wiring because the electricity is not traveling very far. Additionally, the panels are located right on the roof and this reduces the cost of racking. Here, no one will be able to see the array from the ground, which also provides security for the array; no one will be able to access it except maintenance workers. Lastly, this location means easy maintenance. The O&M company simply needs to climb onto the roof and all the panels are accessible for repairs or cleaning.

            However, because the array is located directly on the rooftop, there are some cons. First, there might not be enough roof space to offset the demand of the building. In this instance, another array would have to be installed at a different location. Depending on what method is chosen for securing the racking to the roof, the roof might need to be penetrated. This is usually a safe method but can occasionally result in structural issues with the roof. For this reason, it is important to have an experienced team perform the install ensuring it is done correctly.

            Installing a solar PV array on the roof is ideal for organizations with a large, unobstructed building with a flat roof and minimal shading. Generally a one story building works best; the size of the roof is more likely to be able to offset the demand than if the building were more than one story. Also, the fewer obstructions the better since this will allow the array to be installed as one large array instead of many smaller arrays broken up by vents, little structures, or other obstructions on the roof. Not only will obstructions disrupt the array but so will shading. Shading can be a big problem for solar arrays because a panel will not function if it is shaded and can even shut down other panels depending on the type of inverters used. This means less energy is produced. While trees that may cause shading can be trimmed, shading caused by other structures is not so easy to resolve. 

ground_solar

A ground mount at the Cucamonga Valley Water District in California. 

GROUND

            A ground mount is a great way to provide a large amount of solar electricity while using land that might otherwise be unused.  When installing a ground mount, the client can choose to have the array located near the building or farther away from it, depending on where there is adequate space. One advantage of a ground mount is that it won’t physically impact the building, as a roof mount might. Because of the location, a ground installation is easy to access for repairs or maintenance and is generally fenced in to protect the array from people and animals. Installing solar as a ground mount allows the array to be large enough to meet demand.

            Installing a ground mount can be very rewarding but can also be problematic. Depending on the distance between the array and the building, you may need to use remote net metering which can complicate the interconnection of the array to the utility grid. Additionally, with an array located close to the ground, there is the potential for damage caused by animals or humans. However, these incidences are rare and can be handled appropriately by the O&M company.

            A ground mount is especially beneficial for companies who own large lots of land and want to turn the unused land into a revenue generating system. Additionally, if the roof is not suitable for solar, a ground mount is a great alternative. The roof may not be suitable for several reasons: structural issues, shading/ obstructions, not enough space for solar, or roof material issues.

canopy_solar

A canopy at Plantronics in California.

LOT

            A lot mount, generally referred to as a canopy, is a way to install solar over parking lots or other unused areas of land. It differs from a ground mount because the installation itself is high off the ground, allowing the land underneath to still be used. This type of solar is most often used above parking lots to provide electricity and to shade the cars parked below, which is a nice benefit. Having a solar array directly over the parking lot is a great way to provide charging stations for electric cars – yet another way to embrace renewable electricity. Additionally, lights can be incorporated to use electricity from the array and to light the parking lot at night. Because of the size of a canopy, it will be seen by anyone near your building. This can be beneficial and attract clients who are interested in solar or renewable energy.

            However, having a large solar array near your building could also be considered a downside by anyone who thinks it is unattractive. During the installation, any trees, light posts, or other tall obstacles will have to be removed to make room for the racking. This is usually not a problem, but can make the installation process more costly. A canopy is generally more expensive per watt due to the amount of racking needed to install the panels over 15 feet above the ground.

            The canopy is ideal for companies who have large parking lots and would like to benefit from shaded parking as well as clean, renewable electricity. Additionally, if your company embraces solar and wants to show off their array, a canopy is a great way to show the public that you are choosing to invest in solar and the environment.

 

Whether on the roof, ground, or lot, solar is a wonderful option for generating electricity, saving on your electricity bill, and helping the environment. A roof mount is ideal for companies with a large, flat roof with minimal sharing or obstructions. A ground mount, a great substitution for the roof, is ideal for companies with a building that consumes a large amount of electricity or with a large lot of unused land. The canopy is ideal if a company wishes to shade the parking lot, or install solar and still have a useable area underneath. If you are unsure what installations site would be best for you company, or would like more information, call us at (321) 615-4424.

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Eliza Porter

Eliza Porter

Eliza is the Chief Learning Officer for Clean Footprint. As the Chief Learning Officer, she is responsible for writing and editing blogs, e-books, videos and white papers as well as other learning content created for Clean Footprint’s developer partners and clients. Eliza attended New York University in Paris, France and studied Global Liberal Studies before moving to Florida and joining the Clean Footprint team. She also studied Business and Entrepreneurship at the University of Central Florida.