By Roy L Hales
There are currently approximately 400,000 homes in the U.S. with rooftop solar arrays and by 2024 solar panels may be more common than satellite dishes. In their white paper “The Importance of Reliable Solar Mounting Systems,” Barry Cinnamon, Liz Oh, consortium of experts in the solar industry provide a manual on how to avoid problems like roof leaks, loose panels and defective wiring.
They examined twenty systems in the San Francisco Bay area to gain additional insight. These systems were 10 years old and “still in very good shape”.
Only one in 2,000 panels are known to fail and almost all panels sold in the US are guaranteed to provide 80% of their original rated output after 25 years.
“While rare, damages from poorly installed solar racking can cost homeowners and installers several thousands of dollars. The good news is that by using proper components and taking a few extra steps, installers can prevent pretty much all of these problems,” said Barry Cinnamon, CEO of Cinnamon Solar and primary white paper author.
There principal areas of concern are inverters and mounting systems.
“Since racking and mounting reliability is already very high among quality-focused installers, it’s very easy to get comfortable as an industry and let issues sneak up on us. We wanted to bring more attention to reliability in the racking space since problems there can give the industry a black eye and curb growth if ignored,” said Liz Oh, President of Solar Marketing Group and white paper co-author.
High winds can create an uplift as much as 3,600 pounds on an eight-panel installation. Snow-loads and winds also exert great downward pressure. For these reasons, it is best that the system be bolted directly to underlying rafters.
Fortunately, the vast majority of US roofs were built to accommodate the extra weight that a solar system brings.
Though it is fairly simply to prevent leaks, a small gap can cost a homeowner thousands of dollars. The potential damage can grow to tens of thousands of dollars if large sections of the roof and interior need repairing.
“Well-designed flashings greatly minimize the chances of leaks around installed mounts. Notably, among the 20 homes surveyed, we did not identify any roof leaks from mounting points that were properly flashed – even if some rafters were possibly missed,” the authors reported.
Solar panels and racks must be grounded to minimize fire and shock hazards.
The authors are not aware of any installation that has blown off, but this conceivably could occur if the panels were not fastened properly.
Wind, rain, snow and ice all exact a toll on the panels and their mounting systems.
“Mounting systems must be designed for rooftop solar installations and not for general equipment installations. Components must be listed to the appropriate standards, and compatible with the equipment being installed. All structural components (including fasteners) must be stainless steel or aluminum. Research findings did not uncover any corrosion or structural failures on old systems that used components designed for solar installations.”
The White Paper is free to download and can be found on Solar Marketing Group’s website @ http://www.solarmarketinggroup.com/whitepaper