Commercial Mounting Systems
Vibrant has many ways of finding space for solar panels. Flat roof, sloped roof, side mount and ground systems all have their applications. Here are highlights on each type of system.
Our Engineer Will Check Your Roof
It is extremely important to have a structural engineer check out the undercarriage of your roof prior to installation. Not all cities or counties require an engineer’s stamp on the building permit plans, but Vibrant always uses a structural engineer.
Building Code Rules the Day
The Universal Building Code (UBC) mandates building materials and techniques. The code comes out every few years. Cities and counties decide for themselves when to adopt a new version of the UBC, so which version is in effect varies. There is no notation of solar photovoltaic systems in any version.
Local building code may dictate variations from our standard techniques. For example, Denver suburbs Westminster and Lakewood both require standoffs instead of L feet. This hardware costs more.
Fire department and electrical code regulations are always to be considered, whether or not the local authorities have special strictures. Any competent solar installer will take care of these mandatory details.
Flat Roof Systems
The structural engineer is also need when dealing with flat roofs. Wind load factors are more critical, and there is a wide variety of flat roofing and substrate materials to deal with. Warranty issues come into play as well. Be sure all aspects are handled prior to installation.
Flat Roof Rack
The standard flat composite roof is penetrated into the joists, purlins or other substructure. Standoffs are installed, rails on them, panels on rails.
Ballasted Rack
Instead of penetrations the rack will hold heavy weights, usually of preformed concrete. Ballasted systems are rated for wind loads so be sure to get one that can handle your local conditions. The best ballast system we know of is called Panel Claw. The weights are minimal compared to old-style ballast system.
Membrane Rack
The rack is wrapped in the same membrane material as your roof membrane. It is stapled in place but no penetrations are done. Heat welding secures the membrane to the roof membrane. This system is a bit heavier then a flat roof rack. It is necessary that your membrane-to-membrane mounting system have adequate air flow vent channels to allow heat to escape from under the array. Heat buildup could decay your roof membrane. Vibrant offers a quality membrane racking system that eliminates heat build-up.
Ground and Side Mounts
Side Mounts
Cantilevered window awning can be mounted to most building sides. It is critical that an engineer check out the condition of the wall during the design process.
Outbuildings
Panels could be installed on a detached garage, a barn or any other solid structure. If you have such a structure built to hold the solar array part or all of its cost may be included in the solar project, potentially earning the 30% federal tax credit. We can give you information but we cannot give you tax advice, so be sure to consult your tax professional prior to making decisions regarding the tax credit.
Ground Mounts
Most ground mount systems will require digging holes and pouring concrete into them, to secure either poles or rack bases securely into the ground.
Parking Canopies
Covered parking is a great improvement. Why not have the shade provided by solar panels? As with outbuildings some or all can gain the federal tax credit.
Sloped Roof Systems
Flush Mount
This is our standard mounting system. It takes up the least space and has the lowest visual impact. We penetrate the roof into the joists using a 5/8” lag bolt and standard roofing sealant. The bolt affixes a metal L shaped foot. Metal rails are attached to the L feet, panels to rails. The system sits parallel to the roof, standing four to seven inches off the roof. Vents and pipes cast shadows, so we place panels a bit away from them. We can go over low vents, and in some cases can bend, cut or move small pipes.
Tilt Mount
We add metal legs to the flush mounting to tilt the tops of the panels to gain a better angle to the southern horizon. This adds a bit of cost in labor and materials but gains more output from the panels, as the sun hits them at a better angle as it moves through the southern sky during the day. In Denver the ideal tilt is 40º. Plus or minus 10º makes little difference, so an 8/12 sloped roof, 33.6º, is fine for flush mounting in losing only 1% of output. A 4/12 roof, 18.4º, would need tilt legs in order to not lose 7% of output. If you prefer a flush mount and are okay with outputting 7% less it’s of course okay.
Fin Mount
On slopes that face more to the east or west, in order to get reasonable angle to the south we’d install tilt legs of varying lengths. The profile of a fin-mounted system is much higher but the goal is your having a PV system that outputs the electricity you need.
Shadows
Tilt and fin mount systems will likely have more than one row of panels. Each row casts its own shadow. Therefore the rows must be placed a distance apart so the southern row does not shadow the next row. Distance depends on the slope of the roof and tilt of the panels, but a good rule of thumb is that rows need to be about eight feet apart.
Distance Matters
Note that when the array is more than 50 feet from the meter we will need to install the inverter(s) near the array. DC current degrades dramatically when sent more than 50 feet, so we will convert to AC before sending it further. This often involves trenching, to bury the cable.
Creative Design & Installation
Vibrant’s experts, guided by our LEED Accredited Designer, may be able to come up with other solutions to your particular challenges.