April 25, 2023
Mature industries are characterised by well-developed engineering practices, requirements, high quality administration processes and extremely dependable programs. The solar PV business has usually not achieved this degree of maturity in its buildings and fastener know-how.
During the 2022 RE+ occasion in Anaheim, Calif., this previous September, a analysis staff walked the Exhibit Hall and located many stark examples of business immaturity. They reported the leads to a function unique to Solar Builder journal.
The staff carried out an off-the-cuff survey and noticed widespread misspecification and, in two instances, notably excessive examples of misapplications. In one instance, the staff noticed automobile headliner fasteners, and with the second, a series hyperlink fence element — each non-structural however known as upon to take care of structural integrity.
The significance of fasteners inside PV racking and tracker programs is commonly missed by system designers. Although composed of comparatively easy and cheap parts, fasteners play a essential position within the structural reliability of PV programs.
Joint engineering practices and requirements in structural metal and transportation industries have matured over the previous century and change into extensively adopted. As a outcome, failures of mounted joints (or bolted joints) in buildings and transportation are actually uncommon. In comparability, the solar PV business is comparatively younger and lacks the depth of engineering practices and requirements of different industries. Loose, lacking or damaged bolts in solar are surprisingly widespread. When it occurs, modules can change into broken, indifferent, and even worse, programs can collapse. All of those can improve upkeep prices, scale back system efficiency, or worst of all, create life-safety dangers.
Industry audit underway
A undertaking funded by the Department of Energy, Solar Energy Technology Office (DOE-SETO) is researching this very subject. The analysis staff is made up of a mixture of subject material consultants from academia and business. Among different issues, the staff is working to seek out areas of transferable engineering data from different industries.
The staff not too long ago performed an audit of the solar PV racks and trackers on show at RE+ ’22. The staff checked out 19 completely different racking merchandise and examined 92 bolted joint designs. Of the 92 bolted joints examined, the staff recognized 83 areas of concern, a lot of which have been fairly severe and will probably result in vital monetary loss and questions of safety (for programs close to pedestrians).
The researchers utilized a standard Failure Modes Effects Analysis (FMEA) framework to summarize the doubtless failure results ensuing from the bolted joints examined at RE. Most of the failure results might be labeled as “serious” when it comes to potential monetary and life-safety impacts. Here are two examples of fasteners discovered on the racks and trackers at RE+ ’22, which have been proven to both be ineffective or problematic in different industries.
For the total function, unique to Solar Builder, entry the digital version proper right here. “Problematic” begins on web page 50:
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Researchers: Jon Ness, president, Matrix Engineering Consultants; Gerald Robinson, principal investigator, LBNL; Tracy Becker, affiliate professor, UC Berkeley; James Elsworth, mechanical engineer, NREL; Holden Murphy, engineering scholar, Matrix Engineering
Industry stakeholders battling bolted joint challenges are invited to contact the analysis staff; Gerald Robinson, principal investigator, Lawrence Berkeley National Laboratory, at gtrobinson@lbl.gov.
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