Racking for solar parking, or parking lots filled with solar carport frames, could be mistaken for ground-mount solar racking simply elevated but solar parking canopy design has its own unique complexities, configurations, and safety considerations. Providing the highest quality solar parking canopy means designing a racking solution specifically for that application and will result in a system that more efficiently uses available space; offers higher flexibility in the field; requires less on-site time to install; and maximizes power generation.
Installing a commercial solar carport system is becoming increasingly common due to the advancements in racking technology that have driven down the cost of installation. Maximizing the benefits of solar parking lots starts with choosing the most appropriate and cost-effective solar carport mounting system. This blog post will walk through how to approach solar parking racking pre-design, selection and installation to help customers build an optimized commercial solar carport system.
Pre-Design Considerations for Solar Parking
When approaching solar parking canopy design, there are four main aspects to consider: height, site layout, tilt, water management, spacing and foundation.
Solar Carport Frame Height
The height of the leading edge of the frame depends on what vehicles or machinery will need to pass underneath, such as ambulances, delivery trucks, or school buses. If the solar parking lot needs to allow emergency vehicles to pass, the frame should provide a minimum of 13.5 feet to 14 feet of clearance. In other situations, a lower leading-edge height is sufficient and more cost effective.
Site Layout
Determining the ideal orientation and location of a solar carport mounting system accounts for any potential shading from trees or adjacent structures that could negatively impact production. The system also needs to be designed to consider the standard space of 27 feet between columns and whether there are custom requests for areas such as entry ways. Spacing also depends on soil content, snow loads, wind loads and other factors.
Tilt Considerations
The solar parking shed is designed with a one-degree to seven-degree tilt. When the tilt exceeds seven degrees, there is a larger wind sail effect, requiring larger columns and heavier foundation to compensate. This additional material increases the cost and decreases coverage over the parking area.
Water Management
Properly designed solar parking canopies also help manage snow and rain. Designers consider these questions: Where should water be pushed to to drain? Are gutters, leaders or some roofing system needed? Structures designed for solar parking should offer roofing substrates that are installed underneath the racking and rubber gaskets that go between the panels and help keep water from dripping through the panels.
Solar Parking Structures and Foundations
The solar parking structure is comprised of two structures. The primary structure is attached to a foundation with anchors using an I-beam base design and arrives ready to be installed without needing to weld or drill on site. The secondary structure is the box channel or purlins above that support the solar modules.
The foundation of the solar carport frame is designed with the soil composition in mind. Typically, the I-beam type of foundation meets most needs, but spread footers can be used to offer more stability or helical foundations for both in-the- ground or above-ground column connection. When designing solar parking, it is most cost effective to maximize the amount solar modules and minimize the number of foundations used.
Configuration Types for Commercial Solar Carport Racking
Solar parking frames are now fully customizable with various configurations to fit a customer’s site requirements and limitations.
L-Shape
A fully cantilevered design that is typical for row of parking spaces up against a building or the end of a solar parking lot.
T-Shape
A cantilevered design with three solar panels on each side, spanning the column beams, typically used for a North to South orientation. This is often the most cost-effective solution if the site allows for it.
Y-Shape
This design is typically used when the columns are going East to West and like the T-shape have six solar panels in total. Given the Y-shape, any water will flow toward the center and the columns.
P-Shape
This is a unique design that is often used at school or office building sites where there needs to be coverage over a walkway. It also allows for additional solar modules to be added onto the frame for a total of eight panels.
Long-Span
This solar parking canopy design allows for varied column spacing with 27 feet between the bases on the shorter side and up to 100 feet on the longer side. This design is ideal for parking decks or parking garages where a limited number of columns is ideal for maneuverability.
Installing Solar Parking Structures
As we’ve detailed above, designing a solar parking structure is vastly different than a ground-mount system and installation is no different. Unlike ground-mount or roof-top solar, solar parking lots are being used by the general public and thus installation typically needs to be streamlined, flexible and fast. Solar carport racking designs with minimal components, higher tolerances and pre-punched holes allow for quicker and more flexible installation.
For more information check out our webinar on solar carports.
