SOLAR ENERGY
Designing Solar for High Winds on Challenging Terrain by Yezin Taha
As extreme weather impacts from climate change become increasingly widespread, solar developments are faced with entering more dangerous territory. Further, with available flat land areas becoming increasingly scarce, the industry must now consider project sites with histories of extreme weather events and challenging terrain. With challenging weather and/or terrain becoming the norm for projects, it is imperative that asset owners and EPCs do the appropriate project and product due diligence to select equipment that is capable of thriving in these environments. To align the torque tube straight along the length of the row, the industry traditionally had two ways of approaching challenging terrain: grade the site flat, or implement variable foundation reveal heights. Neither of these options is ideal; they can lead to increased costs, complicated construction, and disturbed land. However, there is a third option of using solar trackers that follow the natural terrain, whatever it may be. This type of tracker eliminates the disadvantages from the other approaches, but requires more diligence in the upfront design. To begin the design process, EPCs and/or developers should generate 3D point files of the foundation locations. From there, racking equipment providers can identify the appropriate technology needed to accommodate the various angle changes early in the design process. This contrasts from typical project timelines, where the completion of a 2D layout during preliminary design activities is sufficient to get an accurate bill of materials. Additional design work on non-flat terrain involves assessing how foundation wind loads are affected by the variable terrain, and accurately locating those foundations along the length of each row. Wind loads are affected by variable terrain; calculations based on wind tunnel studies should be available from the tracker supplier to understand those loads. Foundation northing distances decrease with increasing slope, which can be accounted for in 3D Civil CAD programs. When taking these challenging terrain projects to regions with patterns of extreme weather, such as Kansas, New Hampshire, and Louisiana, dynamic stability and stow strategy are key considerations.
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2022 MAY• JUNE /// www.nacleanenergy.com
