As featured in Solar Builder by Chris Crowell.
Ground conditions have always been a top challenge for solar engineering, procurement and construction (EPC) teams, but more stringent environmental rules have upped the difficulty levels. Luckily, a variety of solar mounting, racking, and tracker systems are up to solving these site challenges.
Mounting ground challenges
Challenging ground conditions – undulating terrain, rocky or soft soils, etc. – are pretty much a given. With rocky or really hard soils, H pile refusals and remediation are a constant risk. “The remediation options for driven piles can be quite expensive, and they can really impact your schedule quite a bit because the velocity of install is slow,” says Chase Anderson with Terrasmart on an episode of The Pitch.
For the often-overlooked issue of frost heave, ground screws are often a great choice. In Maine, for example, Terrasmart installs a lot of projects with ground screws, which can better handle frost heave forces over time.
“Completing this milestone project for the Cincinnati Zoo is a significant achievement for all of us at Terrasmart,” said Terrasmart Chief Sales Officer Yuri Reznikov. “Not only did we deliver our canopy solution on time and within budget, we are also excited about the meaningful impact this project will have for the zoo and its neighboring communities.”
“If we were to do those with driven piles, projects probably wouldn’t pencil out,” Anderson says. “The reason ground screws are so successful in handling frost heave is that the surface area is much smaller. I think it’s three or four times less surface area. So, the force itself is already reduced, but the threads always sit below the frost portion of the soil. All of our tension capacity comes from the threaded section, and we’re able to resist those frost heave forces pretty easily.”
