Contributed by Kayla Harris | DCE Solar communications and marketing manager

One of the more persistent engineering challenges in solar construction is deploying on sloped or uneven terrain. Grade variability drives up civil costs, complicates permitting, and tends to compress installation schedules at exactly the wrong time.

The Old Hill Farm project in Jefferson Valley, New York, developed by Woodfield Renewable Partners, is a concrete example of how selecting racking and foundation systems early in design can prevent those problems from catching up with the project later. With a total system capacity of 6,106,490 watts, this solar installation features 11,414 Canadian Solar modules mounted on DCE Solar’s Long Span Ground Screw racking system. Installation was performed by DCE Services, which handled both mechanical installation and pre-drilling, ensuring seamless project execution.

The Problem

The site’s irregular, steep grade ruled out conventional driven-pile fixed-tilt solutions. Grading the site to the tolerances required by a standard pile system would have significantly increased the civil scope and risked triggering additional environmental review.

Woodfield needed racking that would follow the land as-is, not a civil plan built to make the land fit the racking. DCE Solar’s Long Span fixed-tilt ground mount with a ground screw foundation was selected for exactly that reason. The system is engineered with structurally independent tables, which distribute load independently across the array rather than relying on a continuous baseline grade. That structural independence is what made this site workable without heavy grading.

The solution

DCE Services installed 2,620 ground screws, each 2,100mm in length and manufactured from G115 steel, achieving the embedment targets the geotech report established across variable soil conditions. The structural design was analyzed to ASCE 7-16, with a 105 mph design wind speed and 30 psf ground snow load, both consistent with northeastern U.S. loading requirements for ground-mounted solar projects.

Pre-drilling was executed across the full site before mechanical installation began. This step gets treated as optional on simpler sites, but here it was not. Characterizing subsurface resistance across a sloped footprint before driving a single screw meant the installation team had real soil data to work from, not assumptions. That is what produced consistent embedment across an irregular terrain profile.

The 11,414 Canadian Solar modules were installed at a fixed 15° tilt, with 30 inches of minimum ground clearance maintained across the array. Tilt angle, clearance, and long-span foundation geometry were coordinated in the engineering package to hold consistent inter-row spacing and meet load performance requirements across the analyzed wind and snow conditions.

The project was completed at 6,106,490 WDC, on a site where a conventional pile system would have required a materially different civil scope to function. Limiting grading kept costs down and kept the schedule intact.

Final Assessment

Tyler Bonini, principal at Woodfield Renewable Partners, put it plainly: “Its robust design, coupled with its ability to cover extensive areas with minimal structural components, made it the perfect solution. The system is versatile, durable, and cost-efficient.”

The lessons from Old Hill Farm are straightforward: on sites with visible grade variability, foundation selection is as much a civil cost decision as a structural one. Ground screw systems with longer-span capability reduce the total number of foundations and the civil intervention required to support them. And a geotech is not optional. The pre-drilling strategy that produced consistent embedment here only worked because the subsurface conditions were documented first.

About the Author

Kayla Harris is the communications and marketing manager at DCE Solar, where she has spent five years helping shape and grow the company’s brand from the ground up. Based in North Carolina, Kayla holds a Master’s in Cultural Anthropology, a background that informs her approach to storytelling, audience, and the human side of marketing. As an Indigenous person and human rights activist, she is purpose-driven in everything she does, bringing the same conviction to her advocacy as she does to her work in renewables. Before solar, she honed her craft working with nonprofit organizations, where clear messaging and limited budgets have a way of making you very good, very fast. Kayla believes that the best brands do not just sell, they stand for something.