Flat, easy sites are increasingly rare, making challenging terrain the norm for utility-scale solar. New technologies let developers and EPCs design cost-effective, sustainable, high-performing projects on sloped or uneven land—often without grading.
Grading reshapes land through leveling or cut-and-fill so it meets project specs, but it also adds risk, cost, and environmental impact. Smarter trackers, racking, and installation methods now allow projects to follow the natural landscape instead of forcing the land to fit the site.
To decide whether grading is truly necessary, teams should assess the risks of uneven terrain, compare alternatives for different site conditions, and understand installation impacts. This approach helps maximize economic, environmental, and reputational benefits.
Earthwork costs, longer timelines, subsurface surprises; these are just a few of the potential risks that come with difficult terrain.
- Grading costs: When racking and modules need level foundations to operate, the additional earthwork costs of grading can escalate into multiple six figures per project.
- Longer timelines: Reshaping the land and stabilizing the soil requires extra steps before installation can begin. Even without delays, extensive grading can add months to construction timelines.
- Subsurface risks: The more that ground is manipulated, the more likely it is that unwelcome subsurface surprises will pop up. From refusals and hidden rock to groundwater issues and unstable soil, subsurface conditions can lead to costly change orders, redesigns, and reengineering work.
A bulldozer conducts grading work in a landscape of undulating terrain
Grading specific risks
Beyond challenging terrain, the risks of grading extend beyond the project itself.
- Community pushback: Plans for extensive grading can be met with pushback, protests, and even lawsuits from local communities and special interest groups. According to the Lawrence Berkeley National Laboratory, community pushback was one of the top three reasons that utility scale projects were cancelled, resulting in an average of $2 million in lost sunk costs per project.
- Environmental damage: Mass grading can lead to a wide array of environmental issues, including habitat loss for wildlife and native plants, disruptions to natural drainage, and soil erosion and dust clouds. These negative impacts are often what triggers community response, and they can impact the brand reputation of companies involved. What’s more, the opportunity for a decarbonized and environmentally responsible future is inherent in the premise of clean energy, and minimizing environmental disruption allows stakeholders to uphold this sustainable tenet.
- Project economics: Grading can cause expenses to balloon during permitting and project construction. It also has long-term impacts on project economics. For example, altering natural soil composition and water flow increases the risk of ground instability, which in turn may damage system infrastructure, reduce energy production, and increase O&M costs.
What to look for in terrain assessments
While some amount of grading may still be necessary, evolving technologies and installation methods are providing options for more sophisticated and less invasive grading plans.
Slopes vs. undulating topography
Slope (the degree of incline on a site) and undulating topography (irregular, rolling ground) are two distinct terrain challenges that require grading assessment. From a design and construction standpoint, both influence grading, how foundations are installed, and what kind of racking design can deliver the best balance of performance, cost, and long-term reliability. Undulating topography typically requires more adaptive racking systems and precision planning.
When creating a grading plan for undulating topography or steep slopes, the right racking design ultimately depends on site-specific conditions. A grading window, the area where the top of the foundations should be positioned, is one such condition. The land that falls above the grading window needs to be cut, and the land that falls below needs to be filled. Keeping the top of foundations in the grading window ensures mechanical reliability.
Some representative examples of racking designs and how they impact grading requirements follow.
Fixed-tilt continuous row design offers flexibility when building on slopes or undulating topography. When combined with straight torque tubes, they can minimize challenges presented by subtle grade variations under the site’s trackers.
An example of fixed-tilt continuous row design
On the other hand, fixed-tilt tabled design gives the most freedom in sloping and undulating topography. Because each table in this design stands independently from the other, even in difficult sites, it achieves significantly less grading and smoother installation.
An example of fixed-tilt tabled design
When choosing partners for a project, look for a provider with a larger grading window. The tighter the grading window, the more earthwork is required. Conversely, a larger grading window gives installers more flexibility in placing foundations, reducing the amount of grading needed, speeding installation, and reducing costs.
Key factors in grading decisions
After evaluating grading risks, terrain, and site conditions, these factors can guide decisions on whether and how much to grade.
Timeline: Grading is often one of the longest site-prep steps. Minimizing it allows crews to move straight to racking and module installation, speeding delivery and reducing equipment costs.
Ease of installation: Limiting grading keeps work more predictable. Avoiding subsurface digging reduces surprises and helps projects stay on schedule.
Environmental impact: Minimal grading protects the land, can simplify permitting, and eases post-construction restoration.
Equipment access: Before skipping grading, assess whether crews and machinery can safely move across the site. Steeper terrain may require specialized equipment or adaptive racking.
Long-term maintenance: O&M needs should shape grading plans. Graded sites may introduce new risks, while ungraded sites still need access for inspections and maintenance.
Technological advancements and the wisdom of experience are informing the industry’s path toward next generation solar. Extensive grading may have been the only option for some sites decades ago, but new alternatives can reduce or essentially eliminate the costs and impacts associated with grading, even on the most daunting topographies. These alternatives empower the growth of productive, cost-effective clean energy.
Op-ed provided by Terrasmart
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