guide10 min read

Bad Roof for Solar in Illinois? A Ground Mount Works, Even on a $0-Down Lease

Ryan Cook•August 26, 2026•Updated Sep 13, 2026

If your Illinois roof can't take solar, your yard almost certainly can — and in 2026 that includes the $0-down lease, not just a cash purchase. Expect two things a rooftop customer never hears about: a minimum system size (typically 8 kW on a ground mount versus 4 kW on a roof) and a ground-mount adder of approximately 45 to 50 cents per watt, either priced into the lease rate or added to a cash quote. On an 8 kW array that adder is roughly $3,600 to $4,000, estimated. Illinois Shines pays the same per REC either way.

I get this call a few times a month, usually from somewhere out past Edwardsville or down toward Mount Vernon. The homeowner wants solar, they've watched their Ameren Illinois bill climb, and then somebody tells them their roof won't work. North-facing. Too shaded. Wrong pitch. Twenty-two years old and due for replacement.

Most of them think that's the end of the conversation. It usually isn't — because a lot of these folks have something a Chicago townhouse owner doesn't. They have a yard.

Ground mount in Illinois: the numbers at a glance

Item	Figure	Effective / source
Ground-mount adder (my installer network)	≈ $0.45–$0.50 per watt, est.	2026 partner pricing; typically includes racking, footings, ~25 ft of trenching
Extra trenching beyond the included run	≈ $20 per foot (dirt), est.	2026 partner pricing
Minimum ground-mount size on a $0-down lease	8 kW (roof mount: 4 kW)	2026 lease partner terms
National benchmark: ground vs. rooftop	≈ $2.96/W vs. ≈ $2.60/W, before incentives	EnergySage marketplace data, updated July 9, 2026
Illinois Shines REC value, 0–10 kW	≈ $70.37 (Ameren IL) / ≈ $80.77 (ComEd) per REC, 15-year contract	IPA 2026–27 program year
Customer-owned adder	+$20 per REC, ≤25 kW, cash or finance, no federal credit claimed	Illinois Shines 2026–27 Small DG changes
Federal residential credit	Ended for systems placed in service after Dec 31, 2025	IRS
Ameren Illinois price to compare	11.326¢/kWh (0–800 kWh), June 1–Sept 30, 2026; resets Oct 1	plugin.illinois.gov
ComEd price to compare	10.399¢/kWh, June 1–Sept 30, 2026; resets Oct 1	plugin.illinois.gov

The yard is a real option, not a consolation prize

A ground mount is just what it sounds like. Steel racking set into concrete footings, out in open ground, wired back to the house through a buried trench. Same panels. Same inverters. Same interconnection with Ameren or ComEd.

There's a genuine performance argument for it too. On a roof, you take the angle and direction the builder gave you in 1998. On the ground, you point the array due south at whatever tilt makes sense, and air moves freely underneath, which keeps the panels a little cooler and a little more productive on hot days. If your roof's only clear space faces north, that difference isn't small.

And you can sweep snow off it in February without a ladder. Anyone who's watched a rooftop array sit under six inches of powder for a week understands why that matters.

What a ground mount costs in Illinois

Two ways to look at this, and I'd rather you saw both.

The number I actually quote. In my installer network, a ground mount adds approximately 45 to 50 cents per watt to the base price. That adder usually covers the steel racking, the concrete footings, and the first run of trenching — about 25 feet is typical — with extra dirt trenching running around $20 a foot after that. On an 8 kW array, that's roughly $3,600 to $4,000 more than the same panels on a roof. On 10 kW, approximately $4,500 to $5,000. If the array has to sit 150 feet from the house, budget for the extra trench.

The national benchmark. EnergySage, one of the biggest solar marketplaces, updated its ground-mount figures on July 9, 2026: an average home ground-mounted system of 14.7 kW at about $43,571 before incentives, or roughly $2.96 per watt, against a 12 kW rooftop average of about $31,042, or roughly $2.60 per watt. Read the total fast and you'd think a ground mount costs 40% more. Compare per watt and the gap is about 36 cents — a size difference dressed up as a mounting difference. That's marketplace data, not a quote, but it lands close to what I see on the ground.

Either way, the honest premium is real, it's not nothing, and it's a lot less scary than the headline total.

One more thing about those national numbers. They're almost always quoted "before incentives." That phrase used to carry real weight, back when a homeowner could take 30% off the top with the federal credit. That credit ended for systems placed in service after December 31, 2025. "Before incentives" is now just the price, and any 2026 article still leaning on that framing is quietly a year out of date.

Yes, the $0-down lease covers a ground mount — here's what changes

This is the piece I most want Illinois homeowners to hear, because a lot of people assume the answer is no.

The $0-down lease programs I work with in Ameren and ComEd territory will build a ground-mounted array. Two conditions come with it that a rooftop customer never runs into:

A minimum size. Ground mounts typically have to be at least 8 kW, compared with a 4 kW floor for a roof install. Footings and a trench cost about the same whether they carry 12 panels or 24, so the program needs enough panels on the frame to make the math work. If your usage only supports a 5 kW system, a leased ground mount probably isn't the fit, and I'll tell you that on the first call.

A per-watt adder. That same roughly 45 to 50 cents per watt gets priced into your lease rate instead of paid up front. Your monthly cost on a ground mount runs a little higher than the identical array would on a roof.

What doesn't change: $0 down, maintenance covered, a 25-year term, and a rate as low as $0.10 per kWh that stays predictable for the term — your full 25-year rate schedule is set in the contract before you sign. Against Ameren's all-in residential rate, now averaging around 15.5¢ per kWh and up roughly 94% in five years, the ground-mount version of that comparison still tends to land in the homeowner's favor. Estimates, always; your usage and your lot move the number.

I've watched people get four months into a solar conversation before the minimum or the adder came up. Ask in week one instead: what's your minimum ground-mount size, and what does the adder do to my rate?

Where Illinois pays you back

Illinois Shines pays on production, not on where the panels are bolted. A ground-mounted array earns the same Renewable Energy Credits a rooftop array would.

For the 2026-2027 program year, a system of 10 kW or less earns approximately $70.37 per REC in Ameren Illinois territory and approximately $80.77 per REC in ComEd territory, across a 15-year production contract. One REC is 1,000 kWh produced.

Then there's a wrinkle that favors the ground-mount buyer who goes the cash-or-finance route. Systems of 25 kW or less that are customer-owned, paid with cash or financing, and not claiming a federal tax credit can qualify for roughly $20 more per REC. With the federal residential credit gone, a homeowner buying outright generally isn't claiming one — so that adder is often available to the very person who decided the lease minimum didn't fit.

Run your own numbers on the REC calculator rather than trusting my arithmetic or anyone else's.

The Illinois-specific homework

A few things a national guide can't tell you.

Setbacks. A ground mount is a structure. Your county decides how far it has to sit from property lines, the road, and your septic field. These rules differ meaningfully across Illinois counties. One phone call to county zoning saves a redesign.

Frost. Footings have to go below the frost line, which runs deeper here than in most of the country. That's part of why the concrete costs what it does.

Property taxes. Illinois has a special assessment provision for solar (35 ILCS 200/10-5 and following), and it covers ground mounts — but it generally requires a claim filed with your county's chief county assessment officer. I wrote about how solar affects Illinois property taxes in more detail, and the filing step is the part people miss.

Land you're actually using. Put it where you don't mow, garden, or plant. Obvious until somebody puts an array in the middle of the good pasture.

What I'd do in your shoes

Get the roof assessed properly first. Sometimes "your roof won't work" turns out to mean "your roof needs to be replaced first," which is a different problem with a different fix. Our roof check tool is a reasonable starting point, and I covered the replace-first question in do I need a new roof before solar.

If the roof is genuinely out, price the yard both ways. Ask the lease program for its ground-mount minimum and adder. Ask a cash or finance quote to break out racking and trenching. Then compare the two with the Illinois Shines value included — for a ground mount, that comparison often lands somewhere people don't expect.

The estimates on any of this are estimates. Your roof, your lot, your usage, and your county all move the number.

If you want a straight answer for your specific address, call me at (618) 217-2001 or reach out here. If your roof is the problem, I'll tell you. If the yard is the answer, I'll tell you that too — including when it isn't worth it.

Sources

Plug In Illinois — ComEd Price to Compare (10.399¢/kWh, June 1–Sept 30, 2026): https://plugin.illinois.gov/understanding-the-price-to-compare/price-to-compare-comed.html
Plug In Illinois — Ameren Illinois Price to Compare (11.326¢/kWh 0–800 kWh, June 1–Sept 30, 2026): https://plugin.illinois.gov/understanding-the-price-to-compare/price-to-compare-ameren-illinois.html
Illinois Shines — 2026-27 Small DG category changes (+$20/REC customer-owned adder): https://illinoisshines.com/small-dg-category-changes/
Illinois Shines — Program FAQs (REC definition, 15-year contract): https://illinoisshines.com/faqs/
IRS — Residential Clean Energy Credit (not available for property placed in service after Dec 31, 2025): https://www.irs.gov/credits-deductions/residential-clean-energy-credit
Illinois General Assembly — 35 ILCS 200/10-5, Solar energy systems; definitions (P.A. 102-662, eff. 9-15-21): https://www.ilga.gov/legislation/ilcs/fulltext.asp?DocName=003502000K10-5
Illinois General Assembly — 35 ILCS 200/10-10, Valuation of solar energy systems (claim filed with the chief county assessment officer): https://www.ilga.gov/legislation/ilcs/fulltext.asp?DocName=003502000K10-10
EnergySage — Ground-mounted solar cost data (Tier 3 marketplace benchmark, updated July 9, 2026): https://www.energysage.com/solar/alternatives-to-rooftop-solar/ground-mounted-solar/

Updated September 12, 2026: rewritten to reflect that $0-down lease programs in Illinois do cover ground mounts (with a size minimum and per-watt adder); cost section rebuilt on installer-network pricing with the EnergySage benchmark attributed and dated.

Interactive Tool

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Enter your monthly electric bill for an instant lease-vs-utility estimate built on your numbers — not a national average.

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Utility Rate Escalator: 4.5% per year

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How We Calculate Your Savings

This calculator uses your custom utility rate (default $0.16/kWh for Illinois) with a 4.5% annual escalator compared to our lease rate as low as $0.10/kWh (est.) plus battery backup for 25 years, with the full rate schedule set in your contract. After the 25-year lease, you can keep the system for a low fair-market buyout — then your electricity cost drops to near-zero for the remaining life of the panels. Your actual savings may vary based on your specific usage patterns and system size.

Frequently Asked Questions

Yes, and in rural and small-town Illinois it's more common than most people expect. A ground mount is a steel frame set into concrete footings in your yard, wired back to your house through a buried trench. The panels and inverters are the same ones that would have gone on your roof. What changes is the permitting. A ground mount is a structure, so your county or municipality treats it like one — that means setback rules from property lines, roads, and septic fields, and sometimes a height limit. Setbacks vary a lot between counties in Central and Southern Illinois, so the answer for a five-acre parcel outside Effingham is different from a quarter-acre lot in Belleville. Before you fall in love with a spot in the yard, call your county zoning office and ask two questions: what the setback is, and whether a ground-mounted solar array needs a variance.

In my installer network, a ground mount adds approximately 45 to 50 cents per watt to the base price of the system, and that adder usually includes the racking, the footings, and the first stretch of trenching (about 25 feet is typical, with extra dirt trenching running around $20 per foot). On an 8 kW array that works out to roughly $3,600 to $4,000 more than the same panels on a roof; on 10 kW, approximately $4,500 to $5,000. National marketplace data lands in the same neighborhood: EnergySage's July 2026 figures put ground mounts at about $2.96 per watt versus about $2.60 for rooftop, a gap of roughly 36 cents. Those are estimates, and yours depends on soil, distance to the house, and county permit fees. Ask for the racking and trenching as separate line items so you can see what the yard is costing you.

Yes. The $0-down lease programs I work with in Ameren and ComEd territory will build a ground-mounted array, with two conditions a rooftop customer never hears about. First, a minimum system size: ground mounts typically have to be at least 8 kW, compared with a 4 kW floor for a roof install, because the fixed cost of footings and trenching has to be spread across enough panels to make the numbers work. Second, a per-watt ground-mount adder, roughly 45 to 50 cents per watt, that gets priced into your lease rate rather than paid up front. Your monthly cost on a ground mount will therefore run a little higher than the same size array on a roof. What doesn't change: $0 down, maintenance covered, a 25-year term with your full rate schedule set in the contract before you sign. Ask about the minimum and the adder in your first conversation, not your fourth.

Yes. Illinois Shines pays on production, not on where the panels sit, so mount type doesn't change your Renewable Energy Credit value. For the 2026-2027 program year, a system of 10 kW or less earns approximately $70.37 per REC in Ameren Illinois territory and approximately $80.77 per REC in ComEd territory, on a 15-year production contract. One REC equals 1,000 kWh of production. There's a detail worth knowing here: systems of 25 kW or less that are customer-owned and paid for with cash or financing can qualify for an additional $20 per REC, provided no federal tax credit is claimed on the system. Since the federal residential credit ended for systems placed in service after December 31, 2025, a homeowner buying outright generally isn't claiming one anyway. Ground mounts often end up in that cash-or-finance category, which can make the adder relevant.

Illinois has a special assessment provision for solar energy systems (35 ILCS 200/10-5 and the sections that follow) that generally keeps a solar installation from being taxed on its full added value, and it applies to ground-mounted systems as well as rooftop ones. The provision isn't automatic, though. You typically have to file a claim with your county's chief county assessment officer, and the filing requirements and timing vary by county. I've seen homeowners assume the assessor would handle it and then find the paperwork was never submitted. If you're putting an array in the yard, ask your installer whether they file the assessment paperwork for you or whether it's on you, and get that answer before the system is energized. A ground mount is physically obvious from the road, so it tends to draw an assessor's attention sooner than panels on a back-facing roof slope.