Ground-Mount Solar Foundations and Footings, Explained Simply
Last verified: September 2026
What actually holds a ground array to the earth? Here's a plain tour of the four foundation families — driven posts, concrete piers, ground screws, and ballast — and what steers the choice. No depths or loads guessed. Questions? Call (330) 200-8042.
How a Ground Array Is Anchored
A ground array has to stand against wind, weight, and Ohio's freeze-and-thaw for decades, and its foundation is what keeps it planted. There are four common families: driven steel posts pushed into the soil, concrete piers set in the ground, ground screws turned in with little concrete, and ballasted mounts that weigh the frame down on top with no digging at all. None is best in the abstract — your soil, frost, water table, rock, and slope decide, which is why a soil test or an engineer often guides the call. It's always a licensed, permitted, professional job, and no depths or loads are guessed here. There's a printable 29-page version up top.
Common Questions
1 What are the main types of ground-mount foundations?
Four families cover nearly everything: driven steel posts, concrete piers or footings, ground screws or helical piles, and ballasted mounts that sit on top of the ground. The first three anchor into the earth; ballast weighs the frame down on the surface with no digging.
2 How does the installer choose which one?
Your ground does most of the deciding — soil type, frost, water table, rock, and slope, plus access and permits. Firm, drivable soil often suits driven posts; rock or a high water table may point to ballast or screws. A soil test or an engineer frequently confirms the call.
3 How deep do the footings need to go?
Deep enough to get below where the ground freezes and to carry the loads — but the actual depth is set by your local building department and your engineer for your exact site. I won't guess a number, and you should be cautious of anyone who quotes one off the cuff.
4 Do I need a soil test?
Sometimes. Where the ground is uncertain, a soil (or geotechnical) test reveals a high water table, rock, or swelling clay before anything is built — cheap insurance against a foundation that heaves or settles later. When an installer suggests one, it's usually looking out for you.
5 Can I build the foundation myself to save money?
No, and please don't try. It involves engineered loads, permits, buried utilities, and heavy equipment. Always call 811 before any digging. It's a licensed professional's job start to finish — your role is to understand and evaluate it, which is what these guides are for.
Would You Rather I Just Help?
Foundations are where a lot of a solar quote's cost and confusion live. If a proposal has you puzzled — posts versus ballast, why a soil test, how deep — I'll walk you through it in plain English with nothing to sell you. $99 flat for a visit, 30-day come-back-free.
Would you rather I just do this for you?
No shame in it — plenty of folks would rather hand it off, and that's what I'm here for. I'll come to your home, set it up right, and make sure it's working before I leave. Flat $99 per visit — no jargon, no upsell, and every visit is 30-day come-back-free.
Not a hardware job? I can often fix it remotely for $49 — a secure screen-share, up to 2 hours, that you watch the whole time and can end whenever (included free for $39/mo Support Plan members, and it counts toward the $99 if it turns out I need to come out).