The Evolution of Solar Mounting Technology
For decades, mounting using solar racking has been the standard for rooftop solar installations. However, with the need to reduce installation material and labor costs, combined with new UL 1703 and 2703 standards requiring that modules, racking and roof mounts be tested together to meet fire safety and grounding requirements, mounting system technology is evolving.
Technology Optimizes Total System Strength
While introduction of “rackless” mounting systems promise easier design and faster installations over ordinary solar racking systems, it is important to look at the overall solution capabilities to ensure it will stand the test of time. Rackless systems rely on the strength of the module frame to withstand real-world loads imposed by wind and snow. As a result, to achieve engineering compliance with minimal roof penetrations, installations are limited to landscape orientations. While engineering data for rackless systems may imply they can withstand varying spans and weight loads, the testing is often based on the strength of the components, not the strength of the entire array. The following load test examples show results of rackless systems compared to Spice Solar with Built-in Racking.
Ordinary Module on Rackless Roof Mounts
Conditions: 45 psf (792 lbs), 2155 Pa, Wind Speed <110 mph, Snow <15”
Results: Module permanently deformed, Ground path broken, Module warranty void.
Choosing the Right Technology
Rack Mounting Systems
Ordinary solar panels are designed with the lightest weight frames possible that still meet the requirements of resisting down-force loads (snow), up-force loads (wind) and flexing (generates micro-cracks). And these lightweight frames were designed to be attached with solar racking made of rigid aluminum or steel rails, always supported by at least four points on the modules frames. While systems constructed with solar racking can deliver adequate system strength, they require numerous costly parts, additional labor for design, roof penetrations and assembly, and new UL 1703 and 2703 standards require that modules, racking and roof mounts be tested together to meet fire safety and grounding requirements — no more mix and match.
Rackless Mounting Systems
Rackless mounting systems attempt to reduce costs by eliminating rails, reducing attachment points on the roof, and using special clamps to hold adjacent panels together. Unfortunately, this approach limits the forces that the panels can withstand because there is no strong rack structure supporting the panels. Installations are limited to landscape orientations on composition roofs in low wind and no snow zones. What you save in racking costs is quickly consumed by the extra time required to install more roof attachments. And since the allowable wind/snow loads are limited by the load capacity of the module frames (not the mounting system), there is a risk that the panel warranties will be voided.
Portrait Layout (most common)
Rackless systems in portrait require numerous mounts to adjust for lack of rails or built in racking.
Spice Solar with Built-in-Racking
With over 35 years of rooftop solar experience, we took a holistic view of how solar modules should be installed and created a complete integrated solution. To build a better mounting system, rather than starting with mounting for standard panels, we focused on the solar panel manufacturing process. By redesigning the frames of the solar panels, higher load capacities are achieved — while at the same time reducing costs and supporting installations in all wind and snow zones, in all orientations and on all roof types, with industry-standard roof mounts, flashings and tile hooks. The Spice Solar solution reduces design, equipment and labor costs on every job.
UL-1703 Mechanical Load Test
To achieve UL-1703 compliance, the following factors are involved:
1. Design Load 30 psf plus 50% safety factor (45 psf or 2155 Pa)
» 110 mph wind speed or 15” snow (38 lbs/ft3 density)
» Module must be tested in accordance with manufacturer’s installation instructions
2. All manufacturers test to UL-1703 with attachments at mid-points of long side of frames at bolt-hole locations
» Manufacturers generally do not test to UL-1703 with rackless edge attachments
3. To maintain the module’s warranty, modules must be installed per manufacturer’s installation instructions and tested to UL-1703 with that installation method
Learn more about Spice Solar with Built-in Racking.