How much do solar panels cost in Illinois in 2026?
About $3.62 to $3.73 per watt before incentives. That puts a typical 9.4 kW Illinois home system at about $34,000 to $35,000.
“Per watt” is the total price divided by the system’s size. It works like price per square foot for a house. It lets you compare a 6 kW quote with a 12 kW quote.
Two numbers matter most. Berkeley Lab, a U.S. Department of Energy lab, tracks what people really paid. Its U.S. median for 2025 was $3.62 per watt. The State of Illinois makes its own estimate, and almost nobody quotes it. The Illinois Power Agency puts a home system at $3.73 per watt in the ComEd area and $3.66 in the Ameren area.
- Berkeley Lab, 20th percentile Cheapest fifth of U.S. homes, 2025 $2.74
- Berkeley Lab, cash buyers U.S. median, 2025 $2.98
- Berkeley Lab, all buyers U.S. median, 2025 $3.62
- Illinois estimate, Ameren area Illinois Power Agency, 2026 $3.66
- Illinois estimate, ComEd area Illinois Power Agency, 2026 $3.73
- Berkeley Lab, loan buyers U.S. median, 2025 $4.51
- Berkeley Lab, 80th percentile Priciest fifth starts here, 2025 $4.87
Berkeley Lab figures are U.S. prices paid in 2025, in 2025 dollars, for systems homeowners owned. The Illinois figures are the state’s model for 2026. All are per DC watt, the panels’ rated size.
Prices fell in 2025. Berkeley Lab found the median dropped about $0.48 per watt after inflation. Cash prices fell the most, about $0.63. Loan prices fell only about $0.25.
What does a whole solar system cost in Illinois?
Multiply the price per watt by the size. A typical Illinois home system is 9.4 kW, so it costs about $34,000 to $35,000 before incentives.
Illinois homes get bigger systems than most. Berkeley Lab’s 2025 median for Illinois single-family homes was 9.36 kW, about 9.4. The U.S. median for single-family homes was 7.9 kW. Illinois also gets less sun than states like Arizona, so it takes more panels to make the same power.
| System size (DC) | ComEd area, state estimate | Ameren area, state estimate | At the U.S. median paid |
|---|---|---|---|
| 6 kW | $22,404 | $21,942 | $21,720 |
| 7 kW | $26,138 | $25,599 | $25,340 |
| 8 kW | $29,872 | $29,256 | $28,960 |
| 9.36 kW (typical Illinois home) | $34,950 | $34,230 | $33,883 |
| 10 kW | $37,340 | $36,570 | $36,200 |
| 12 kW | $44,808 | $43,884 | $43,440 |
State estimate: Illinois Power Agency cost per DC kilowatt ($3,734 ComEd area, $3,657 Ameren area, 2026 dollars) times size. U.S. median: Berkeley Lab’s $3.62 per watt for 2025. No battery. Bigger systems often cost a little less per watt.
Your own size comes from your bills, not the average. The average Illinois home uses about 693 kWh a month, from the U.S. Energy Information Administration. Covering that takes about 7.3 kW in the ComEd area and about 6.3 kW in the Ameren area, where the sun produces a bit more. Here’s how to size a system from your own usage, and how your bill compares with the average Illinois electric bill.
What will solar cost me after incentives?
About $16,600 in the ComEd area and $15,300 in the Ameren area for a 9.4 kW system you own, if your installer passes the full credit value to you. If it keeps that money, you pay about $32,100.
Three things cut what solar costs you. The first two are big. The third is small but real.
ComEd and Ameren pay $300 for every DC kilowatt, through 2029. On the typical 9.36 kW system, that’s $2,808. How the ComEd rebate works.
The state buys your system’s solar credits for 15 years. On 9.36 kW, that’s about $15,600 to $16,100. Who gets that money.
Illinois law keeps solar from raising your assessed value. You must file with your county. How to file.
Our math on the state’s numbers, not a quote. Credits use the state’s solar output estimate for each area and lose 0.5% a year over the 15-year contract: about 154 credits in the ComEd area and 178 in the Ameren area, at $80.77 per credit in the ComEd area and $70.37 in the Ameren area, plus the $20 owner bonus (2026–27 prices, systems up to 10 kW AC).
| 9.36 kW system you own | ComEd area | Ameren area |
|---|---|---|
| Price before incentives (state estimate) | $34,950 | $34,230 |
| Utility rebate, $300 per kW | −$2,808 | −$2,808 |
| Illinois Shines credits over 15 years, with the $20 owner bonus | −$15,560 | −$16,101 |
| You pay, if the credit money reaches you | $16,582 | $15,321 |
| You pay, if the installer keeps the credit money | $32,142 | $31,422 |
Every incentive in one place: Illinois solar incentives 2026.
Why can two quotes for the same system be $15,000 apart?
Because the state’s credit money goes to the Approved Vendor, your installer or its partner, not to you. It reaches you only as a lower price, if the vendor passes it on. On a typical system that’s about $15,600 to $16,100, so two quotes for the same system can be $15,000 apart.
- Illinois Shines Buys your system’s solar credits for 15 years
- Approved Vendor Your installer or its partner gets the payments
- Paid over time Half when the system turns on, the rest over 6 years
- Your price Lower, only if the vendor passes it on
Illinois Shines is the state’s solar program. It pays for one solar credit, called a REC, for every 1,000 kWh your panels make. The money goes to an Approved Vendor, the company registered with the program. For new 2026 contracts, half is paid when the system turns on. The rest comes in equal payments over six years.
So ask every installer one question: “How many dollars of Illinois Shines credit value is in my price?” Get the answer in writing. The state also requires a disclosure form before you sign. Read it. Here’s how Illinois Shines works and how to check that a vendor is approved.
Why do so few people buy now? The state set credit prices assuming the 30% federal tax credit. Homeowners lost that credit after 2025. Leasing companies can still use a business version. That helps explain why leases and power purchase agreements now lead. The $20 owner bonus only makes up part of the gap.
Is the quote I have in a normal range?
Two quick checks. First, see where your quote lands among what people really paid in 2025. Then see what you’d pay after Illinois incentives.
Step 1 · Is my quote in a normal range?
Turn your quote into dollars per watt and see where it lands among real 2025 prices. It runs in your browser, and we don’t ask for your name. If you start the free check, your size and price per watt carry over so you don’t retype them.
Step 2 · What would I pay after incentives?
Uses the state’s own numbers. Change anything. If you entered a quote above, we use it.
Your utilityHow you’d pay for itCredit money in your priceIf your installer keeps the credit money, you pay about $15,600 more.
Our estimate from the Illinois Power Agency’s cost model, Illinois Shines credit prices with the $20 owner bonus, the $300-per-kW rebate and October 2026 power prices. Not a quote. Payback assumes you use 55% of the power as it’s made, at today’s prices. Above about 12 kW DC (10 kW AC), credits use the lower price for 10 to 25 kW AC systems: $79.21 in the ComEd area and $60.92 in the Ameren area.
Want the numbers for your own roof? The free eligibility check looks at your roof, usage and utility together. If solar isn’t a fit, it says so.
See if my home qualifiesHow does the price you pay change payback?
The credit money in your price cuts payback about in half. About 10 to 11 years in the ComEd area and 8 to 9 years in the Ameren area for a 9.4 kW system you own, if the credit money reaches you. If the installer keeps it, payback stretches to about 18 to 22 years in the ComEd area.
Dark line: savings at today’s prices. Light line: if prices rise 2.5% a year, the state disclosure form’s high case. Dots show payback at today’s prices.
Here’s how we got there. A 9.4 kW system in the ComEd area makes about 10,700 kWh a year. The state’s disclosure form assumes a home uses about 55% of that as it’s made. The rest goes to the grid. At October 2026 rates, that’s worth about $1,546 in year one.
Power you send to the grid earns less than power you use. Since 2025, new systems get credit at the supply price, about 10.2¢ per kWh. You pay about 18¢ for power you buy. So a kWh you export is worth about 43% less than one you use yourself.
Brighter sun and similar prices: about 9 years if the credits reach you.
Getting the credit value in your price cuts payback roughly in half.
If prices rise 2.5% a year, payback comes about 1 to 4 years sooner.
Run your own numbers with the Illinois solar payback calculator. What solar saves also depends on how your utility credits exports: ComEd net metering and Ameren net metering. Some charges stay on the bill no matter what: your electric bill after solar.
What makes one solar quote higher than another?
Mostly the installer, then the equipment. Among the 100 biggest U.S. home installers in 2025, typical prices ran from $2.40 to $6.30 per watt. No single part moves the price that much.
- Battery added +$1.45
- Ground mount instead of roof +$0.40
- DC optimizers +$0.40
- Microinverters +$0.12
- New construction (lowers it) −$0.71
- Each extra kW of size (lowers it) −$0.21
Berkeley Lab, Tracking the Sun 2024 Edition, the lab’s latest model of this kind. These factors explain only part of why prices differ. Use them as a guide, not a price list.
A battery is the biggest single line. If one quote includes storage and another doesn’t, that can be almost the whole gap. For cash buyers in 2025, a battery added about $2.10 per watt, or about $19,700 on a 9.4 kW system. In Illinois, 17% of new home systems in 2025 had a battery, up from 3% in 2024. Utilities pay $300 per kWh toward one, with strings attached. See the ComEd battery rebate, every Illinois battery incentive and whether a battery is worth it.
Your roof can add cost. An older roof may need replacing first. Shade cuts how much power you get. See what your roof needs and whether your roof is too shaded.
The questions that separate a good quote from a bad one are in how to vet an Illinois solar quote.
What are you actually paying for?
Hardware is the smaller part. In the state’s model, panels and inverters are about a third of the price. Labor, electrical work, permits and company costs are the rest.
- Equipment: panels and inverters $1,236/kW
- Installation and labor $1,158/kW
- Interconnection $158/kW
- Development costs and company fee $1,182/kW
| Cost part | ComEd area | Ameren area |
|---|---|---|
| Equipment: panels and inverters | $1,236/kW | $1,236/kW |
| Installation and labor | $1,158/kW | $1,081/kW |
| Interconnection | $158/kW | $158/kW |
| Development costs and company fee | $1,182/kW | $1,182/kW |
| Total | $3,734/kW | $3,657/kW |
Illinois Power Agency, Appendix D to the 2026 Long-Term Plan, Table D-2. every figure is in 2026 dollars per DC kW. The equipment line is the same statewide. The whole ComEd-versus-Ameren gap is labor.
Connecting a home system to the grid is cheap for you. Most homes use the Level 1 process. The application fee is $50, and state rules set the standard Level 1 cost at $200. The state’s model carries a bigger $158-per-kW line for interconnection. Its text cites the $200 figure but doesn’t reconcile the two. If a quote lists interconnection, ask what it covers.
Local permits are part of the soft costs too. Here’s how they work in Chicago and Aurora.
Why does solar cost more in Illinois?
Labor. The state’s model puts Illinois construction wages at 132% of the U.S. median. Labor in the ComEd area runs 130% of the Ameren area, so northern Illinois costs more.
- Wages 32% above the U.S. median
- ComEd-area labor 30% above the Ameren area
- No price drop assumed since 2022, plus 12% inflation
- Extra cost for tariffs on imported equipment
- Getting 3 or more quotes
- Paying cash, or comparing loan and cash prices
- Getting the credit value written into the price
- A simple, sunny roof
So a quote that looks high next to a national number may just be an Illinois quote. Comparison sites often show lower numbers because they publish quote averages, not prices paid. Berkeley Lab says other benchmarks match its 20th percentile, the cheapest fifth of the market. Several pages that still rank for Illinois solar costs also subtract the 30% federal credit that homeowners lost after 2025. Check the date and the math behind any number before you use it.
How much more does solar cost with a loan?
About $14,300 more on a typical system. In 2025, loan-financed systems had a median price of $4.51 per watt; cash buyers paid $2.98. Many solar loans hide a dealer fee inside the price.
Here’s how it works. The lender pays the installer less than the price you sign for. The difference is the fee. It lets the lender advertise a low interest rate. The Consumer Financial Protection Bureau found these hidden fees usually run 10% to 30% of the cash price, and can top 50%.
What does solar cost if you lease instead?
Little or no money upfront, then a monthly payment, often with a yearly increase. The contract matters more than the price per watt. Most new Illinois systems are now leased or on a power purchase agreement. Only about 7% of small-system applications since June 1, 2026 were owned by the homeowner, paid in cash or with a loan.
- You get the $300-per-kW rebate
- Your system can earn the $20 owner bonus, set through May 31, 2027
- The savings are yours
- No federal tax credit after 2025
- Little or no money upfront
- The company can still use a business tax credit
- The rebate and credits usually go to the company
- Watch the monthly payment and yearly increase
The 30% federal credit for homeowners 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 one?). Berkeley Lab counts 58% of Illinois home systems in 2025 as owned by someone other than the homeowner, up from 45% in 2024.
With a lease or a power purchase agreement (PPA), compare the monthly payment, the yearly increase and the total over the contract. Here’s the full math: solar lease vs PPA vs buying in Illinois.
Illinois solar cost FAQ
How much do solar panels cost in Illinois in 2026?
A typical Illinois home system is about 9.4 kW. It costs about $34,000 to $35,000 before incentives, or about $3.62 to $3.73 per watt. The $3.62 is the U.S. median price people paid in 2025, from Berkeley Lab. The $3.66 to $3.73 is the State of Illinois’ own estimate for Ameren and ComEd areas.
How much does solar cost after incentives in Illinois?
For a 9.4 kW system you own, about $16,600 in the ComEd area and $15,300 in the Ameren area. That counts the $300-per-kW utility rebate and the full Illinois Shines credit value, including the $20 owner bonus. If your installer keeps the credit money, it’s closer to $32,100 and $31,400.
What is the price per watt for solar in Illinois?
About $3.62 to $3.73 per watt before incentives. Berkeley Lab found a U.S. median of $3.62 per watt for homes in 2025. Illinois’ own model puts it at $3.73 in the ComEd area and $3.66 in the Ameren area. Cash buyers paid less: a median of $2.98.
Who gets the Illinois Shines credit money?
Not you, directly. Illinois Shines pays your installer’s Approved Vendor for the system’s solar credits. Half comes when the system turns on and the rest over six years. It reaches you only as a lower price, so ask for the dollar amount in writing. How Illinois Shines pays →
How long does solar take to pay for itself in Illinois?
For a 9.4 kW system, about 10 to 11 years in the ComEd area and 8 to 9 years in the Ameren area, if the credit money reaches you. If the installer keeps it, it’s about 18 to 22 years in the ComEd area and 15 to 18 years in the Ameren area. These are our estimates at October 2026 prices. Run your own payback →
What size solar system does a typical Illinois home get?
About 9.4 kW. That’s Berkeley Lab’s 2025 median for Illinois single-family homes (9.36 kW). It’s bigger than the U.S. single-family median of 7.9 kW. A home that uses an average amount of power, about 693 kWh a month, needs about 6.3 to 7.3 kW. Size a system from your own bills →
Why do comparison sites show a lower price?
Most show quote averages, not prices people actually paid. Berkeley Lab says other price benchmarks line up with its 20th percentile, the cheapest fifth of the market. For 2025 that was $2.74 per watt, well under the $3.62 median.
Does solar cost more in Illinois than the national average?
By the state’s own model, yes. Illinois construction wages run 132% of the national median. Labor in the ComEd area costs 30% more than in the Ameren area. Equipment costs the same statewide.
Is the 30% federal solar tax credit still available in 2026?
Not for a homeowner who buys a system. The residential credit ended for spending after December 31, 2025. A separate business credit still helps leases and power purchase agreements, under its own deadlines. What ended, and what’s left →
How much more do loan buyers pay for solar?
In 2025, the median loan-financed system cost $4.51 per watt, versus $2.98 for cash: about $14,300 more on a typical 9.36 kW system. Berkeley Lab says part of that gap may be loan fees. Ask for both prices in writing. How dealer fees work →
How much does a battery add to a solar quote?
For cash buyers in 2025, about $2.10 per watt of solar. On a 9.4 kW system, that’s about $19,700. Illinois utilities pay $300 per kWh toward a battery, but the rebate comes with a five-year virtual power plant commitment. Is a solar battery worth it? →
What does interconnection cost in Illinois?
For most home systems, the Level 1 application fee is $50. State rules set the standard Level 1 cost at $200. If your system needs small grid upgrades, the utility’s own fees apply.
Is it cheaper to buy or lease solar in Illinois?
It depends on the contract. Buying earns the $20-per-credit owner bonus, set through May 31, 2027 and paid through your price, but no federal credit. A lease or power purchase agreement costs little upfront, so compare the monthly payment and the yearly increase instead. Lease vs PPA vs buying, full-term math →
How much does a 10 kW solar system cost in Illinois?
About $37,300 in the ComEd area and $36,600 in the Ameren area before incentives, by the state’s estimate. After the $3,000 rebate and the full Illinois Shines credit value, about $17,700 and $16,400. If the installer keeps the credit money, about $34,300 and $33,600.
How much do solar panels cost in Chicago?
Chicago is in the ComEd area, where the state estimates $3.73 per watt. That’s about $34,950 for a typical 9.36 kW system before incentives, and about $16,600 after if the credit value reaches you. How Chicago solar permits work →
How much do solar panels cost for a 2,000-square-foot house?
Square feet don’t set the price. Your yearly power use and your sunny roof space do. Two 2,000-square-foot homes can need systems that differ by half. Start from your last 12 months of bills.
Did solar prices go down in 2025?
Yes. Berkeley Lab found prices people paid fell about $0.48 per watt in 2025, after inflation. Cash prices fell more, about $0.63 per watt. Loan prices fell only about $0.25.
The terms, in plain English
- Price per watt
- The total price divided by the system’s size in watts. It works like price per square foot for a house, so you can compare quotes for different sizes.
- kW and kWh
- A kilowatt (kW) is a system’s size. A kilowatt-hour (kWh) is the power it makes over time. A 9.4 kW system makes about 10,700 to 12,300 kWh a year in Illinois.
- DC and AC rating
- DC is the panels’ rated size. AC is what the inverter puts out, which is lower. Every price on this page is per DC watt.
- Solar credit (REC)
- A Renewable Energy Credit. Illinois Shines buys one for every 1,000 kWh your system makes, for 15 years.
- Approved Vendor
- The company registered with Illinois Shines that gets the credit money. It’s often your installer or its partner.
- Owner bonus (adder)
- An extra $20 per credit on systems the homeowner owns, paid to the Approved Vendor with the rest of the credit money. It’s set for the program year that ends May 31, 2027.
- Dealer fee
- A hidden charge added to a solar loan so the lender can show a low interest rate. It makes the financed price higher than the cash price.
- Payback
- How many years the savings on your power bill take to add up to what you paid.
Find out what solar would cost on your roof.
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Sources and updates
Sources (20)
- Lawrence Berkeley National Laboratory — U.S. Distributed Solar and Storage: 2026 Data Update (PDF) (August 2026; read October 14, 2026: 2025 prices, the $0.48 drop, cash and loan prices, the battery premium, and the top-100 installer range)
- Lawrence Berkeley National Laboratory — Tracking the Sun data tool (2026 update files; read October 14, 2026: the 20th, 50th and 80th percentiles, Illinois and U.S. single-family system sizes (9.36 and 7.89 kW), Illinois battery and lease shares, and the lab’s count of Illinois price records)
- Lawrence Berkeley National Laboratory — Tracking the Sun, 2024 Edition (PDF) (the price-driver model and the 20th-percentile finding)
- Illinois Power Agency — Appendix D, REC Pricing Model, 2026 Long-Term Plan (PDF) (filed October 20, 2025, kept in the approved plan: cost per kW and its parts in Table D-2, labor multipliers, capacity factors)
- Illinois Power Agency — 2026 Long-Term Plan, as modified (PDF) (June 2026: REC prices, the owner adder for the 2026–27 program year, the payment schedule)
- Illinois Shines — Final 2026–27 REC Prices (PDF) ($80.77 ComEd area and $70.37 Ameren area, up to 10 kW AC)
- Illinois Shines — 2026–27 Program Guidebook (PDF) (April 17, 2026: the customer-owned adder rules and how credits are counted)
- Illinois Shines — Project status and capacity dashboard (read October 14, 2026: 158.08 of 236.71 MW of small-system capacity open, no waitlist)
- Illinois Shines — Project Application Report 1 (spreadsheet) (October 14, 2026; our count of small-system applications by owner type since June 1, 2026)
- Illinois Shines — Utility rates used in disclosure forms, October 2026 (spreadsheet) (retail and supply rates for ComEd and Ameren, used in our payback estimate)
- Illinois Shines — Updated disclosure forms (January 2025: the share of solar a home uses on site, which our payback estimate uses)
- Illinois Shines — October update on application processing (October 8, 2026: 6- and 11-week review times)
- Illinois General Assembly — 220 ILCS 5/16-107.6 (as amended by Public Acts 104-0458 and 104-0477: $300 per kW of DC solar through December 31, 2029, then $250)
- Ameren Illinois — Customer-owned solar (the $300-per-kW-DC solar rebate)
- ComEd news release — distributed generation rebates pass $350 million (August 4, 2026, via Business Wire)
- 83 Illinois Administrative Code 466.90 and Appendix A (the $200 standard Level 1 cost and the $50 application fee)
- Internal Revenue Service — FAQs on Public Law 119-21 (the residential clean energy credit ends for spending after December 31, 2025)
- U.S. Energy Information Administration — Table 5A, average monthly use (PDF) (693 kWh a month in Illinois)
- Consumer Financial Protection Bureau — Issue Spotlight: Solar Financing (August 7, 2024: hidden fees of 10% to 30% of the cash price)
- Illinois General Assembly — 35 ILCS 200/10-10 (the solar property-tax valuation)
Changelog · last updated October 25, 2026 · 4 updates
- October 25, 2026: Added links to the free solar and installer shortlist pages.
- October 15, 2026: Rewritten and redesigned. Re-checked every figure at its source. Updated Berkeley Lab prices to 2025 installs ($3.62 per watt median, $2.74 to $4.87 middle band), switched the typical Illinois system from 7 kW to Berkeley Lab’s 9.4 kW Illinois median, and added the cash and loan medians, Illinois battery and lease shares, open Illinois Shines capacity and review times. Corrected the interconnection note. New quote checker, after-incentive estimator, payback chart and cost charts. Later the same day: made clear the $20 owner bonus is paid to the Approved Vendor, fixed the quote checker for quotes that already take off the credit value, showed the per-credit prices, and added answers for 10 kW systems and Chicago.
- September 29, 2026: Rewritten to be easier to read, with a key-numbers table, a cost-after-incentives example, a payback range and a section on loan versus cash prices.
- August 3, 2026: Published.
How to cite: The Day Company review team, “How much do solar panels cost in Illinois?,” The Day Company, updated October 15, 2026. https://theday.company/answers/solar-panel-cost-illinois
The Day Company is not a government agency, utility, ComEd, Ameren, Illinois Shines, the Illinois Power Agency, the Illinois Commerce Commission, Berkeley Lab or the IRS, and does not imply affiliation with or endorsement by any of them. Utility names identify service areas only. Nothing here is tax, legal or financial advice. Prices, credit values and payback years are estimates built from public sources, not a quote or a promise of savings. Figures were last reviewed in October 2026; confirm current numbers with the source cited before you sign.