Fasteners are a key but often overlooked aspect of racking system installation and maintenance. NEXTracker, one of STANLEY® Engineered Fastening’s premier customers, designs, manufactures, builds, and services the world’s most advanced single-axis solar tracker systems for small to utility-scale power plants around the world. As the cost of panels drop, improving fastener efficiencies have proven to be an unexpected opportunity to save time, money and labor on the installation and maintenance of their solar plants.
NEXTracker has performed considerable cost evaluations of the tracker portion of operations and maintenance (O&M) budgets on sites small and large. O&M costs represent the annual expenditures required to operate and maintain a solar CSP plant over its lifetime of 30 years. In their analyses, they’ve found that conventional linked-row trackers typically use 85% more fasteners than are used on their NX Horizon™ self-powered trackers. That’s because the majority of these fasteners are permanent and “swaged” or fastened, requiring little or no maintenance.
In order to deliver the best value and highest performance to our customers, we invest in new technologies that will reduce installation cost and improve long term durability and reliability.— Dan ShugarChief Executive Officer, NEXTrackerMaintaining the system hardware of a panel’s mounting structure can be a tedious and costly process. Dispatching crews to check the torque on screws or lubricate joints are activities that can add thousands of hours to an annual O&M budget, but in a centralized single-axis tracker (SAT) it must be done since failure of a single component can impact system performance dramatically.
“In order to deliver the best value and highest performance to our customers, we invest in new technologies that will reduce installation cost and improve long term durability and reliability,” states NEXTracker CEO Dan Shugar. “We are always looking for ways to reduce our environmental impact by eliminating waste and improving our operating efficiency.”
System hardware that does not require torquing, but instead relies on the tension between components will reduce the need for manual checks. Torquing, the twisting force required to spin a nut up a bolt, is by nature inexact because of the many factors that can affect friction—from surface texture to debris, rust and humidity. By contrast, “tension” involves the use of battery-powered or hydraulic tools to stretch screws and swage to fasten bolts to a structure. ln fact, the swaging of a lockbolt is five times stronger than its nut-and·bolt counterpart fastening system. Regular nuts and bolts have a gap which can cause loosening by vibration.
Fastener installation and maintenance may not be the most expensive component of the solar tracking system. But NEXTracker knows that improving fastener efficiencies by tapping into proven and emerging fastening technologies can lead to big O&M savings and enhanced protection against extreme weather risk