Solar Answers → Buying & Financing
How much do solar panels cost in Illinois?
A typical 7 kW home solar system in Illinois costs about $21,000 to $28,000 before incentives. That's roughly $3 to $4 per watt. The state's own estimate is $26,138 in ComEd territory. Rebates and state solar credits can cut that to about $12,400. If your installer keeps the credit money, it's closer to $24,000. The 30% federal tax credit for homeowners ended after 2025.
What does "per watt" mean? It's the total price divided by the system's size in watts — like price per square foot for a house. It lets you compare quotes for systems of different sizes.
Where you land in that range depends mostly on who installs it, how big the system is, your roof, and whether a battery is included. Below are the real numbers, what comes off the price and how long payback takes — plus a tool that shows where your quote sits.
Independent public sources we cite and link — The Day Company is not affiliated with or endorsed by any of them. We are an Illinois solar and battery information resource and a lead-generation business.
Illinois solar costs at a glance
Swipe the table sideways to see every column →
| Key number | Figure | Where it comes from |
|---|---|---|
| Typical 7 kW home system, before incentives | About $21,000 to $28,000 | 7 kW at $3 to $4 per watt |
| Price per watt, before incentives | About $3 to $4 | Comparison sites ~$2.96–$3.16 (Sept 2026); state estimate $3.66–$3.73; U.S. median paid $4.00 in 2024, down about $0.50 in 2025 after inflation |
| State estimate, 7 kW system | $26,138 (ComEd) · $25,599 (Ameren) | Illinois Power Agency, 2026 Long-Term Plan |
| 7 kW after rebate and full solar-credit value | About $12,400 (ComEd) · $11,500 (Ameren) | Worked out below |
| Utility solar rebate | $300 per kW | ComEd and Ameren Illinois |
| Illinois Shines solar-credit (REC) price, up to 10 kW | $80.77 (ComEd) · $70.37 (Ameren), +$20 if you own the system | Illinois Power Agency, 2026–27 program year |
| Typical payback | About 9 to 18 years | Our calculator at October 2026 electricity prices |
| 30% federal credit for homeowners | Ended December 31, 2025 | Public Law 119-21 |
How much do solar panels cost in Illinois in 2026?
About $21,000 to $28,000 for a typical 7 kW system, or roughly $3 to $4 per watt, before incentives. Quote-comparison sites put Illinois near the bottom of that range. The state's own estimate, and what people actually paid nationally, sit near the top.
The State of Illinois publishes its own number, and almost nobody quotes it. The Illinois Power Agency, which sets Illinois Shines credit prices, estimates what a typical home system costs in its 2026 Long-Term Plan: $3,734 per kilowatt in ComEd territory and $3,657 in Ameren territory. The state uses that estimate to set what your solar credits are worth.
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| Reference point | Figure | What the number is | As of |
|---|---|---|---|
| Illinois Power Agency — ComEd territory (Group B) | $3.734/W | State estimate for a typical home system | 2026 Long-Term Plan (Oct 2025) |
| Illinois Power Agency — Ameren territory (Group A) | $3.657/W | Same estimate, lower labor cost | 2026 Long-Term Plan (Oct 2025) |
| Berkeley Lab — U.S. home median | $4.00/W | Prices actually paid, before incentives | 2024 installs |
| Berkeley Lab — U.S. middle 60% | $3.00 – $5.20/W | Where most systems fall | 2024 installs |
| Berkeley Lab — change in 2025 | About −$0.50/W | Prices paid fell, after inflation | 2025 installs (Aug 2026 update) |
| Comparison and review sites — Illinois | $2.96 – $3.16/W | Quote averages and marketplace data | Surveyed Sept 29, 2026 |
All figures are per DC watt — the panels' rated power. A quote's "system size" may be a DC or an AC rating, and the two aren't interchangeable. Ask which one yours uses before comparing it to anything here. We don't republish or endorse any single comparison site's figure.
What does a whole system cost before incentives?
Multiply the per-watt figure by the system size. A typical Illinois home uses about 8,300 kWh a year and needs roughly a 7 kW system — close to the 7.7 kW national median for 2025. Larger homes, electric heat or an EV push that up.
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| System size (DC) | Ameren, state estimate | ComEd, state estimate | Comparison sites |
|---|---|---|---|
| 6 kW | $21,942 | $22,404 | ~$17,800 – $19,000 |
| 7 kW (typical home) | $25,599 | $26,138 | ~$20,700 – $22,100 |
| 8 kW | $29,256 | $29,872 | ~$23,700 – $25,300 |
| 10 kW | $36,570 | $37,340 | ~$29,600 – $31,600 |
| 12 kW | $43,884 | $44,808 | ~$35,500 – $37,900 |
State estimate: Illinois Power Agency cost per DC kilowatt ($3,657 Ameren, $3,734 ComEd, 2026 dollars) times system size. Comparison sites: the $2.96–$3.16 per-watt range surveyed September 29, 2026, times system size. Before incentives, no battery. Usage: the U.S. Energy Information Administration puts the average Illinois home at 693 kWh a month — how your bill compares: the average electric bill in Illinois.
A quote near the right-hand column isn't automatically good or bad news. It may mean a competitive installer, a simple roof, or a smaller job than the state assumes. Sizing comes from your own usage, not the average: how many solar panels you need in Illinois.
What will solar cost me after incentives?
About half the sticker price — if your installer passes the Illinois Shines value through to you. Here is the math for a typical 7 kW system you own.
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| 7 kW system, bought outright | ComEd territory | Ameren territory |
|---|---|---|
| Before incentives (state estimate) | $26,138 | $25,599 |
| Utility rebate ($300 per kW) | −$2,100 | −$2,100 |
| Illinois Shines solar-credit (REC) value over 15 years | about −$11,600 | about −$12,000 |
| After incentives — installer passes all credit value to you | about $12,400 | about $11,500 |
| After incentives — installer keeps the credit value | about $24,000 | about $23,500 |
Our arithmetic, not a quote. Credit value uses the state's own estimate of how much power panels make in each area (a 13% capacity factor for ComEd, 15% for Ameren). It allows for panels losing 0.5% of output a year over the 15-year credit term — about 115 and 133 credits. Each is valued at $80.77 or $70.37, plus $20 when you own the system. The property-tax protection below isn't counted.
Why the "if"? Illinois Shines pays for your system's solar credits (RECs). The money goes to the installer's Approved Vendor — the company registered with the program — not to you. Half is paid when the system turns on and the rest over six years. It reaches you only as a lower price. How much of it an installer passes through is the biggest reason two quotes for the same system can differ by thousands. Ask for it in dollars, in writing. More on how that works: Illinois Shines, explained, and who really gets the REC money: is solar worth it in Illinois?
What else comes off the price?
- Utility rebate: ComEd and Ameren each pay $300 per kW for qualifying solar with a smart inverter — the details: ComEd's solar rebate, explained.
- Property tax: Illinois keeps solar from raising your assessment, but you have to file for it. See do solar panels raise property taxes in Illinois?
- Everything in one place: Illinois solar incentives 2026.
One timing note: REC capacity for small systems has run out before a program year ended. In 2024–25 it was fully used by May 6, 2025. Blocks reopen each June, but availability across a whole year isn't guaranteed.
How long does solar take to pay for itself in Illinois?
About 9 to 18 years for a typical 7 kW system you own. At October 2026 electricity prices, our calculator puts it at roughly 10 to 18 years in ComEd territory. In Ameren territory it's about 9 to 17 years.
The low end assumes your installer passes the full REC value through; the high end assumes it keeps it. Payback figures elsewhere vary widely, and several still subtract the 30% federal credit that homeowners can no longer claim. Run it for your own bill: the Illinois solar payback calculator.
What solar saves depends on your electricity price and on how your utility credits the power you send back: ComEd net metering and Ameren net metering. Some charges stay on the bill either way — your electric bill after solar. Prices keep moving, too. ComEd's price reset on October 1, 2026 to 10.103¢ per kWh (what changed). Why bills are high right now: ComEd and Ameren. Production also dips in the darker months: how solar performs through an Illinois winter.
Not sure whether your roof is even a candidate?
Free, about a minute, no obligation. If solar isn't right for your roof or your usage, it tells you so instead of booking a sales call.
Check my eligibility →Is the quote I already have in a reasonable range?
Turn it into dollars per watt and see where it lands. It takes five seconds, and it's how the industry itself compares systems of different sizes.
That number is only half the picture. It can't tell you whether your roof, your usage and your utility actually support the system it's pricing. The eligibility check is free, takes about a minute, and will tell you if the answer is no.
Check my eligibility →Nothing you type is sent or stored by this page — the math runs in your browser. If you continue to the eligibility check, your figures come with you so you don't have to retype them. This tool compares your figure with published reference points and nothing else. It doesn't know your roof, usage, equipment, warranty or contract terms, and it isn't a judgment about whether a quote is fair. Berkeley Lab's benchmarks here are for 2024 installs; its August 2026 update found prices fell about $0.50 per watt in 2025, so a fair 2026 quote may land a little lower.
What makes one quote higher than another?
Mostly the installer — then the equipment. Berkeley Lab measured how specific choices moved the price per watt on 266,903 home systems installed in 2023.
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| What changes | Estimated effect on price per watt |
|---|---|
| Battery storage added | +$1.45/W |
| Ground-mounted instead of roof-mounted | +$0.40/W |
| DC optimizers | +$0.40/W |
| Microinverters | +$0.12/W |
| Each additional kilowatt of system size | −$0.21/W |
| New construction rather than retrofit | −$0.71/W |
Lawrence Berkeley National Laboratory, Tracking the Sun 2024 Edition — national figures for one year. These factors explain only part of why prices differ, so treat them as a guide, not a pricing formula.
- The installer matters most. Among the 100 largest home installers in 2025, typical prices ran from $2.40 to $6.30 per watt — a wider spread than any equipment choice. The questions that separate a good quote from a bad one: how to vet an Illinois solar quote.
- A battery is the biggest single line. If one quote includes storage and another doesn't, that may be almost the entire gap. Berkeley Lab's 2025 data put the typical extra cost of a battery at about $2.10 per watt for cash buyers. Illinois utilities pay $300 per kWh toward storage, with strings attached: the ComEd battery rebate and every Illinois battery incentive. Whether a battery is worth it at all is its own question: is a home battery worth it in Illinois? You may also see no-upfront-cost battery offers: free home battery offers, explained.
- Bigger systems cost less per watt, so a per-watt comparison between a 6 kW and a 12 kW quote isn't apples to apples.
- Your roof can add cost. An older roof may need replacing first, and shade cuts how much a system produces. See solar roof requirements and whether your roof gets enough sun.
Why is a solar loan price higher than the cash price?
Many solar loans carry a dealer fee — a charge built into the financed price so the lender can advertise a low interest rate. It's why the same system can cost thousands more on a loan than for cash.
Berkeley Lab's August 2026 data shows the same pattern nationally: loan-financed systems were priced well above cash purchases, partly because loan fees are rolled into the price. Ask every installer for the cash price and the financed price, side by side and in writing. The gap between them is the real cost of the loan. How dealer fees work and what to ask: why is my solar loan bigger than the cash price? And before you sign with anyone: how to verify a solar installer is legitimate.
What are you actually paying for?
Hardware is the smaller part, which surprises most people. In the state's model, panels and inverters are about a third of the price; labor, electrical work and soft costs are the rest.
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| Cost component | Ameren territory | ComEd territory |
|---|---|---|
| Equipment — panels and inverters | $1,236/kW | $1,236/kW |
| Installation — racking, wiring, electrical work, labor | $1,081/kW | $1,158/kW |
| Interconnection | $158/kW | $158/kW |
| Development costs and fee | $1,182/kW | $1,182/kW |
| Total | $3,657/kW | $3,734/kW |
Illinois Power Agency, Appendix D to the 2026 Long-Term Plan, Table D-2, in 2026 dollars per DC kilowatt. The equipment line is identical statewide — the whole ComEd-versus-Ameren gap is labor.
One line doesn't add up, and we'd rather say so. Connecting a typical home system to the grid — a "Level 1 interconnection" — has a $50 application fee. Illinois Commerce Commission rules cap the customer's total Level 1 cost at $200 — far below the model's interconnection line. The Plan doesn't explain the gap, so if a quote itemizes interconnection, ask what it covers. Local permitting is part of the soft costs too — how it works in Chicago and in Aurora.
Why does solar cost more in Illinois than the national average?
Labor, and the state says so. Its model puts Illinois construction wages at 132% of the national median. Labor in ComEd territory runs 130% of Ameren territory, which is why northern Illinois prices higher.
Two more assumptions are worth knowing before anyone tells you prices are still falling. The model holds home equipment costs flat from 2022 to 2026 while applying 112% inflation over the same years. It also adds a tariff-driven increase on imported parts. The price drops of the 2010s have flattened, and Illinois labor costs more than most of the country. So a quote that looks high next to a national number may simply be an Illinois quote.
Why do comparison sites show a lower number?
Because most publish quote averages, not prices actually paid. Berkeley Lab notes that other published price benchmarks match its 20th percentile — the cheapest fifth of the market — more closely than its median.
Comparison-site range surveyed September 29, 2026; Illinois Power Agency, 2026 Long-Term Plan, Appendix D Table D-2; Berkeley Lab national home median, 2024 installs.
The Berkeley Lab figures on this page are national. The lab reports a state only when it has at least 20 usable price records, and it leaves leases and power purchase agreements out of its price data. Its August 2026 update found prices fell about $0.50 per watt in 2025 after inflation. Several pages that still rank for Illinois solar costs also subtract the 30% federal credit that homeowners can no longer claim. Check the date and the assumptions behind any number before you negotiate against it.
How much do solar panels cost for a 2,000-square-foot house?
Square footage is the wrong starting point — no primary source publishes a cost-per-square-foot rule for solar. Your system size — and so your price — depends on how much electricity you use in a year. It also depends on how much unshaded roof faces the right way.
Two 2,000-square-foot homes on the same street can need systems that differ by half. Start from your last twelve months of usage instead. What size solar system you need in Illinois walks the method, and the tables above turn the result into a price.
Is it cheaper to buy your own solar panels or lease them?
It depends on the contract terms more than the price per watt. The 30% federal credit for homeowners who buy their own system ended for systems installed after December 31, 2025 (did the solar tax credit end?). Illinois never had a state solar tax credit to replace it (does Illinois have a state solar tax credit?).
Buying still earns the $20-per-REC customer-owned adder in Illinois Shines for qualifying systems up to 25 kW. A lease or power purchase agreement takes the equipment cost off your hands. Then the monthly payment and yearly escalator matter more than the price per watt. A separate business-side federal credit still applies to third-party-owned projects under its own deadlines. The full comparison: solar lease vs PPA vs buying in Illinois.
Illinois solar cost FAQ
How much do solar panels cost in Illinois in 2026?
About $21,000 to $28,000 for a typical 7 kW system before incentives — roughly $3 to $4 per watt. The Illinois Power Agency's 2026 model puts it at $3.73 per watt in ComEd territory and $3.66 in Ameren territory. Berkeley Lab's national median for 2024 installs was $4.00 per watt.
How much does solar cost after incentives in Illinois?
For a 7 kW system in ComEd territory, the state's estimate is $26,138. The $300-per-kW utility rebate and the Illinois Shines solar-credit value can bring it down to about $12,400. That assumes the installer passes all of the credit value through; if it keeps it, the cost is about $24,000. In Ameren territory the same math runs about $11,500 to $23,500.
Why is the state's figure higher than the ones on comparison sites?
Comparison sites generally publish quote averages — about $2.96 to $3.16 per watt for Illinois in September 2026 — rather than prices actually paid. Berkeley Lab notes that other published benchmarks line up more closely with its 20th percentile than its median, the cheapest fifth of the market. The state's figure is a full cost basis, not a best-case one.
Does solar cost more in Illinois than the national average?
By the state's own modeling, yes. The Illinois Power Agency puts Illinois construction wages at 132% of the national median. It also puts labor in ComEd territory at 130% of Ameren territory. Equipment costs are modeled the same statewide.
What makes one Illinois solar quote higher than another?
Mostly the installer, then the equipment. Berkeley Lab's 2023 model estimates that adding a battery raises the price by about $1.45 per watt. Ground-mounting and DC optimizers add about $0.40 each, and microinverters about $0.12. Each extra kilowatt of size lowers it by about $0.21. Installer choice moves it more than any of those: typical prices across the 100 largest home installers ranged from $2.40 to $6.30 per watt in 2025.
Why is my solar loan price higher than the cash price?
Many solar loans include a dealer fee: a charge built into the financed price so the lender can advertise a lower interest rate. That's why the same system can cost thousands more financed than paid in cash. Ask every installer for both prices in writing — the gap between them is the real cost of the loan.
How much do solar panels cost for a 2,000-square-foot house?
Floor area doesn't determine the answer, and no primary source publishes a cost-per-square-foot rule for solar. System size depends on how much electricity you use in a year and how much unshaded roof faces the right way. Two homes of the same size can need systems that differ by half.
Is the 30% federal solar tax credit still available in 2026?
Not for a homeowner buying their own system. The residential clean energy credit ended for expenditures after December 31, 2025, which the Illinois Power Agency confirms in its 2026 Long-Term Plan. A separate business-side credit still applies to commercial and third-party-owned projects under its own deadlines and sourcing rules.
What does interconnection cost in Illinois?
Typical home systems use the Level 1 track, and its application fee is $50. Illinois Commerce Commission rules cap a customer's total Level 1 cost at $200. The Illinois Power Agency's estimate carries a much larger interconnection line and doesn't explain why. Ask any installer what their interconnection line covers.
Is it cheaper to buy solar panels or lease them in Illinois?
It depends on the contract terms rather than the price per watt. Buying now carries no federal residential credit but can earn the $20-per-REC customer-owned adder in Illinois Shines for qualifying systems up to 25 kW. A lease or power purchase agreement takes the equipment cost off your hands. Then the monthly payment and yearly escalator are the numbers that matter.
Do solar panels increase property taxes in Illinois?
Illinois law keeps a qualifying solar system from raising your property's assessed value. It isn't automatic, though — you have to file with your county assessor. The filing is covered in our guide to solar and property taxes in Illinois.
What is the payback period for solar in Illinois?
About 9 to 18 years for a typical 7 kW system. At October 2026 electricity prices, our calculator puts it at about 10 to 18 years in ComEd territory. In Ameren territory it's about 9 to 17 years. The low end assumes the installer passes the full Illinois Shines REC value through; the high end assumes it keeps it.
Did solar prices go down in 2025?
Yes, nationally. Berkeley Lab's August 2026 data update found that prices paid for home solar fell about $0.50 per watt from 2024 to 2025 after inflation, with bigger drops for cash purchases. Loan-financed systems were priced well above cash purchases, partly because loan fees are rolled into the price.
Related answers
More answers: do panels survive hail? · what an HOA can and can’t block · selling a house with solar · solar panels in Peoria · ComEd Hourly Pricing with solar · ComEd’s virtual power plant · Ameren’s virtual power plant · the ComEd solar guide · Illinois solar facts.
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Free eligibility check · ComEd & Ameren · No obligationThe Day Company is an Illinois solar and battery information resource and a lead-generation business. Information you submit may be used by our review team and one authorized partner to contact you about your request. Checking eligibility creates no obligation, and no figure on this site is a quote or a guarantee. How we’re funded and how we source figures: our editorial standards.
Sources
Sources · 15 documents behind this page
- Illinois Power Agency — Appendix D, REC Pricing Model, 2026 Long-Term Renewable Resources Procurement Plan (PDF) — October 2025: cost per kilowatt and its components (Table D-2), Illinois labor multipliers, capacity factors, REC prices, federal credit status
- Illinois Shines — Program Documents — 2026–27 REC prices and the customer-owned adder
- Lawrence Berkeley National Laboratory — U.S. Distributed Solar and Storage, 2025 Data Update (PDF) — October 2025: the 2024 national median and middle-60% band
- Lawrence Berkeley National Laboratory — U.S. Distributed Solar and Storage, 2026 Data Update (PDF) — August 2026: the 2025 price drop, the loan-versus-cash gap, the battery premium, the installer price range and the 7.7 kW median system
- Lawrence Berkeley National Laboratory — Tracking the Sun, 2024 Edition (PDF) — the price-driver model and the 20th-percentile finding
- Lawrence Berkeley National Laboratory — Tracking the Sun data tool — state-level data and the 20-record reporting rule
- ComEd — Solar rebates — the $300-per-kW solar rebate
- Ameren Illinois — Customer-owned solar — the $300-per-kW solar and $300-per-kWh storage rebates
- Illinois General Assembly — Public Act 104-0458 — the REC payment schedule: half at energization, the rest over six years
- Illinois General Assembly — 35 ILCS 200/10-10 — the solar property-tax valuation
- Internal Revenue Service — Public Law 119-21 FAQs — the end of the residential clean energy credit
- U.S. Energy Information Administration — average monthly residential use, Table 5A (PDF) — 693 kWh a month in Illinois
- 83 Illinois Administrative Code Part 466 — Illinois Commerce Commission interconnection rules, checked September 29, 2026: the $50 Level 1 application fee (Appendix A) and the $200 standardized Level 1 cost (Section 466.90(c))
- National Renewable Energy Laboratory — Q1 2023 Solar Benchmark Cost Report — the component data the Illinois Power Agency adjusts for Illinois
- National solar comparison and review sites — Illinois cost-per-watt figures surveyed September 29, 2026; we don't republish or endorse any single site's figure
How to cite this page: The Day Company, "How much do solar panels cost in Illinois?", theday.company/answers/solar-panel-cost-illinois, last reviewed September 29, 2026.
Update triggers: this page is revised when the Illinois Power Agency publishes new cost or REC figures, when Berkeley Lab releases its next data update, and when utility rebate amounts change.
Changelog · last updated September 29, 2026 · 2 updates
- September 29, 2026 — Rewritten to be easier to read. The page now opens with a plain price range and adds a key-numbers table, a cost-after-incentives example, a payback range from our calculator and a section on loan versus cash prices. Refreshed the comparison-site survey ($2.96–$3.16 per watt), updated Berkeley Lab figures to its August 2026 data release, updated the October 2026 electricity price, and corrected how Illinois Shines REC value reaches homeowners — it arrives as a lower price, if the installer passes it through. Added a share row, tap-to-open sources and changelog, links to every related guide, and a site-wide header and footer update.
- August 3, 2026 — Published.