Types of Solar Mounting Systems: Carport vs. Ground Mount vs. DIY—and the Cost Lesson I Learned the Hard Way

If someone asks you which is the largest planet in our solar system, the answer is Jupiter. No debate. If they ask which type of solar mounting system makes sense for your site, it's not that simple. I've been handling mounting-system orders for nine years, and I've personally made—and documented—14 significant mistakes, totaling roughly $38,000 in wasted budget. Now I maintain our team's checklist so nobody else repeats my errors.

This article is a comparison between two paths that look similar on paper: DIY ground mount solar racking and pre-engineered mounting systems, including carport mounting systems. Not because one is always better, but because the way they're priced is different, and that difference catches people off guard.

What this comparison is really about

When people ask me about the types of solar mounting systems, they usually expect a simple answer: roof or ground. That's part of it. But the comparison I end up having with real customers is "buy an engineered system" versus "build it from a kit." The mounting system is often the least understood line item in a solar project, which makes it the easiest place to hide costs. According to NREL's PV system cost benchmarks (nrel.gov), racking and mounting hardware is usually a single-digit percentage of total installed cost. That's exactly why it gets ignored—until it causes a change order.

I don't have hard data on how many DIY ground mount solar racking projects end up costing more than expected. But based on the 23 ground-mount projects I've reviewed in the last five years, my sense is that about 3 out of 4 first-time DIY installs exceed the hardware budget by at least 30%. That's anecdotal. I wish I had tracked it more carefully.

The quote nobody should trust

The first mistake I made as a buyer was comparing sticker prices. A quote for a DIY ground mount solar racking kit might say $3,200 for a 12-panel system. I want to say that was the price back in 2021, but don't quote me on that. The vendor's list didn't include concrete, thread rods, grounding lugs, clips, engineering stamps, or shipping. (Should mention: the shipping was $260 and the ground screws were another $340.)

An engineered system quote, on the other hand, usually includes the whole package. It may look more expensive. In my experience, it often isn't, because the "cheap" quote is missing things.

I've learned to ask 'what's NOT included' before 'what's the price.'

The vendor who lists all fees upfront—even if the total looks higher—usually costs less in the end.

Engineering and permits—the expensive surprise

I skipped a geotechnical report once because I thought, "what are the odds someone checks?" (This was on a small DIY ground mount in 2022.) The building department signed off, but the rack settled over the winter. The re-leveling cost $890 plus a 1-week delay. That's when I learned that a mounting system is not just steel in the ground; it's a structural element.

Pre-engineered mounting systems from reputable suppliers come with load tables and sometimes stamped drawings. But here's the catch: "engineering included" can mean anything. On a carport project in Q3 2024, our supplier said drawings were included. The first set turned out to be a generic installation manual, not a site-specific plan. The building department rejected it. We lost 10 days waiting for the real drawings.

Material quality and the "it's just steel" myth

I'm not going to tell you that steel is worse than aluminum or that ballasted systems are worse than penetrated ones. They're not. The material choice depends on your roof, your soil, and your wind zone. But DIY ground mount racking has a consistency problem. You're not just choosing a material; you're also choosing your own quality control.

I once trusted a DIY racking manual that called for a torque spec of "make it snug." Eight months later, three of the rails had shifted in a wind event. The panels didn't fail, but the scratches were permanent. That was a $780 repair and a lesson in checking torque values. (Surprise, surprise: a pre-engineered system would have included a torque table.)

Here's the part that surprises people: a well-built DIY system can be just as strong as an engineered one. If you know exactly what you're doing, if your soil is stable, and if you follow every torque spec, the hardware itself can be fine. The risk isn't the steel. It's the variability.

Labor time—where DIY racking quietly loses

The math that catches people goes like this: a DIY ground mount solar racking kit saves $700 in hardware, but it takes three extra days to install. If you are paying installers—or if your own time is worth anything—that $700 is gone by lunch.

An engineered mounting system is designed to be installed in a specific order, with labeled parts and a clear manual. Our fastest carport install was 3 days. The DIY rack next to it took 6 days, and we still had to re-order missing bolts.

At least, that's been my experience with ground mounts up to 30kW. Larger projects are a different animal.

Add-ons, battery, and monitoring

Add-ons are where hidden costs hide. Most people choose a mounting system without thinking about what will be attached to it later: conduit, optimizer rails, inverters, batteries.

A few years ago, we added an energy monitor GW US version to a ground-mounted array. On a pre-engineered rack, the wire management was already there. The monitor took four hours. On the DIY ground mount next to it, we needed a separate conduit run, two junction boxes, and a weekend of improvisation. That one choice added maybe $450 to a "budget" system.

Carport mounting systems: a special case

Carport mounting systems deserve their own advice. They're not just taller ground mounts. The wind loads are different, the anchoring is different, and the structure has to protect cars, not just panels. If you're getting a carport quote, compare the racking specification with the same total cost mindset.

I've seen projects where the lower bid on carport racking was chosen to save $0.03 per watt, only for an engineer to up-size steel later because the uplift calculation failed. The change order was larger than the original cost difference. That's the kind of expense that never shows up in a comparison spreadsheet until it's too late.

So which should you choose?

The answer isn't as clean as the answer to which is the largest planet in our solar system (Jupiter). It depends on your site, your crew, and your risk tolerance.

Choose DIY ground mount solar racking if you have the time to do the engineering homework, the tools to do the job, a forgiving local inspector, and a site with stable soil. Choose a pre-engineered system if you're working on a financed project, a carport, a commercial rooftop, or any site where a delay costs more than the hardware.

If you're shopping for mounting systems, get the "what's not included" list before you get the price. Transparent pricing is a sign that the vendor has thought about the whole install, not just the aluminum and steel. Prices as of early 2025; verify current rates.