The solar industry is constantly progressing. From solar panels that track the movement of the sun to solar fields that span multiple square miles, the industry continues to develop new technologies and approaches to maximize the affordability and capacity of solar generation. Advancements are not solely confined to equipment, though. Construction methods have improved as well, specifically with grading design for solar projects.
Grading is the leveling of land, a practice widely used in the solar industry to provide a planar surface for solar installation. In the solar industry’s infancy, heavy grading was required to completely flatten the ground beneath the solar panels because of limitations with the racking support systems. However, as the size and footprint of solar facilities increased, the industry has learned that flat grading can add major costs to the project because of the effort and equipment needed to move large quantities of earth. Additionally, grading can cause significant impacts to drainage patterns, vegetation and environmentally sensitive areas, requiring costly mitigation measures and longer project timelines.
The industry noticed that grading was one of the few areas within a solar project where costs varied depending on the site’s location. Generally, the electrical components and solar panels are commodities for which costs are fixed and don’t change between project sites. This led to innovations in the industry to develop racking support systems that could tolerate undulations in the ground and would minimize the amount of grading required to support solar construction.
As a result, grading design has become an integral part of the solar project process. Rather than attempting to achieve the flattest and clearest surface possible for these expansive fields, grading designers evaluate the natural slope and vegetation to determine an installation approach with minimal land disturbance.
The benefits of optimizing the grading design for solar projects can be extensive:
- Reduce installation costs by eliminating mass earth moving and drainage design features.
- Save time with streamlined upfront permitting and environmental studies by keeping the land intact.
- Reduce long-term maintenance costs by maintaining the ground’s natural equilibrium and reducing future drainage or erosion issues.
- Improve public perception of the project by limiting disturbances to the land and vegetation.
Of course, not all areas considered for solar installations are conducive to minimal grading. Land that doesn’t maintain a consistent slope might not meet the tolerances for tracking systems, and heavily vegetative areas or those within a flood plain might require significantly elevated steel pile heights that outweigh the cost of grading. Fortunately, full-service, integrated engineer-procure-construct (EPC) firms like Burns & McDonnell offer preliminary site evaluations and upfront grading designs to help solar project owners make informed decisions. By assessing the condition and drainage patterns of the existing land, and adjusting the design to accommodate, owners can save time and money while achieving a solar facility that can stand up to the tests of time and Mother Nature.
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