Solar in Illinois depends on paperwork more than sunshine. When the Illinois Shines payment for your system’s output reaches you, a typical home system can pay for itself in about 5 years in our example. When it does not, the same system takes about 18. Get the payment terms in writing before you sign.
Typical payback, with the Shines paymentAbout 5 years
With or without itAbout 5 to 18 years
Typical owned 9.23 kW Illinois system at $28,152 cash (EcoGen Solar Cost Index, September 2026), ComEd, with the Shines payment and utility rebate reaching you. Without the Shines payment it takes about 18 years. Uses the EIA average price and three assumptions of ours: 40% of the solar power used at home as it is made, a 10¢ credit for the 60% sent to the grid, and $277 a year in owner costs. See the math.
- Shines payment: the block price, the total, and who receives it, written into the contract.
- Utility: ComEd, Ameren, MidAmerican or a co-op. Each has its own rebate and export rules.
- Time in home: about 5 years to pay back with the payment, far longer without it.
2026 rules: new home systems get no 30% federal homeowner credit (IRS). New ComEd, Ameren and MidAmerican customers since January 1, 2025 earn supply-only credits for exported power.
How we checked this guide
Program prices come from the Illinois Shines 2026-27 price list, rebates from the ComEd and Ameren tariffs, and the electricity price from the U.S. Energy Information Administration. The example system is the EcoGen Solar Cost Index typical Illinois home. Where we had to assume a number, the page says so.
The writer and checker shown above are EcoGen staff. EcoGen is paid when homeowners request quotes, which is explained beside the quote form. Read our editorial standards.
When does Illinois solar pay, and when should you wait?
The Illinois Shines program buys the renewable energy credits (RECs) your panels create, one per 1,000 kWh, for 15 years of output. That payment is large enough to change the answer, and it only lands for projects registered correctly, submitted while capacity is open, and contracted so the value reaches you. Read each row across.
Shines payment
Worth a closer look
The contract names the block price, the estimated payment and who receives it.
Pause and check
The proposal cannot say what the payment is, or the company keeps it with no lower price.
Check next: the REC block, submission date, and who absorbs a shortfall if the block fills.
Utility territory
Worth a closer look
Your quote models your utility, its $300 per kW rebate and supply-only export credits.
Pause and check
The quote uses a generic rate, or assumes exports earn the full retail price.
Check next: your utility name on the quote and the export credit it assumed.
Roof and time in home
Worth a closer look
An unshaded roof with years of life, and you plan to stay past payback.
Pause and check
The roof needs work soon, heavy shade, or a move within about 5 years.
Check next: the roof’s age, a shade report and your likely moving date.
Price and financing
Worth a closer look
A competitive cash price near the Index’s $28,152 for 9.23 kW ($3.05 per watt), paid in cash or a low-fee loan.
Pause and check
A loan with a dealer fee that quietly takes back what the Shines payment gave.
Check next: the cash price next to the financed price, plus APR, fees and term.
Installer
Worth a closer look
A registered Illinois Shines approved vendor that submits promptly.
Pause and check
A seller who is not on the program’s vendor list, or cannot give a submission date.
Check next: the vendor’s status on the Illinois Shines approved vendor list.
The two Illinois answers, side by side
Simple payback is the years your savings take to cover what you paid: net cost divided by yearly savings. Here it is for the typical Illinois home system when the Shines payment reaches you.
- Cash price
- $28,152
- Confirmed incentives
- $20,809
- Year-one production
- 12,331 kWh
- Used at home / exported
- 40% / 60%
- Average price (EIA, 12 months)
- $0.1879/kWh
- Export credit
- $0.10/kWh
- Owner-cost allowance
- $277/yr
- Used-at-home value
12,331 × 40% × $0.1879$927/yr - Export value
12,331 × 60% × $0.10$740/yr - Yearly savings after owner costs
$927 + $740 − $277$1,390/yr - Simple cash payback
($28,152 − $20,809) ÷ $1,390about 5.3 years
Inputs: the EcoGen Solar Cost Index typical Illinois system (9.23 kW, $28,152 cash, September 2026; 1,336 kWh per kW a year), the 2026-27 Shines payment for an owned ComEd system (about $18,040, about 179 RECs) and the utility rebate ($2,769). The 18.79¢ EIA average includes fixed charges spread over every kWh, so the rate you really avoid is likely a little lower. Three inputs are our assumptions: that 40% of the solar power is used at home as it is made and 60% is sent to the grid, a 10¢ export credit, and $277 a year in owner costs ($30 per kW, including a reserve for a new inverter). The 40/60 split is a planning assumption based on home-use research, not a measured Illinois average. The 10¢ is a yearly illustration of ComEd’s supply credit, which moves each month with its Purchased Electricity Adjustment: in October 2026 the 10.103¢ price to compare minus 1.551¢ came to about 8.55¢. Ameren credits its own rates, 10.441¢ on the first 800 kWh and 8.262¢ above, so do not read this ComEd case as an Ameren forecast. Half the Shines payment arrives at start-up and the rest over 6 years; simple payback counts it all at the start.
Now take the Shines payment away. Late submission, a full block, or a contract where the company keeps it with no lower price all lead here. The savings do not change. The net cost does.
| Scenario | Incentives | Net cost | Yearly savings | Simple payback |
|---|---|---|---|---|
| Shines payment reaches you | $20,809 | $7,343 | $1,390 | about 5.3 years |
| Shines payment missed | $2,769 | $25,383 | $1,390 | about 18.3 years |
That gap is why your installer’s program skill is a money question in Illinois, not a nice extra. Prices in the example are for the 2026-27 program year and can change for later blocks.
Run your own Illinois numbers
The tool starts with the Shines case above. Put in the numbers from your own quote and press Calculate. Set incentives to the rebate alone to see the no-Shines case. Nothing you enter is sent anywhere.
Example result
about 5.3 years
simple cash payback
- Used-at-home value
- $927/yr
- Export value
- $740/yr
- Owner costs
- −$277/yr
- Yearly savings
- $1,390/yr
- Net cost
- $7,343
Starts with the Shines case above. Flat first-year values; the Shines payment really arrives over 6 years, and rates, panel wear and repairs will change the result.
What your exported power earns in Illinois
Power you use at home saves the full price you would have paid. Since January 1, 2025, power new ComEd, Ameren and MidAmerican customers send to the grid earns credit for the supply part of the price only. Delivery charges stay on your bill no matter how much you export. Credit you do not use keeps rolling forward to later bills.
Used at home: 4,932 kWh. Each one replaces power you would have bought, so it saves the full variable rate ($0.1879 here).
Sent to the grid: 7,399 kWh. These earn whatever your utility pays for exports ($0.10 here). That can be far less.
Homes connected by December 31, 2024 keep full retail credits for 30 years. A legacy ComEd customer who takes the new solar rebate ends your full bill credits, so ask before you add panels to an older system. Illinois homes paid an average of 18.79¢ per kWh from August 2025 to July 2026 (EIA).
See which side of the line your roof lands on
An Illinois quote should show both cases: with and without the Shines payment. Ask for both.
Solar providers that serve your area may contact you, and they pay EcoGen for the introduction. How we make money.
Who keeps the Shines payment when you finance?
Owning the panels, with cash or a loan, is the only way the Shines payment can reach you. In a lease or power purchase agreement (PPA), the company owns the system and its RECs, and leases get no owner adder.
| Option | Who owns the panels | Upfront | Ongoing | Check before signing |
|---|---|---|---|---|
| Cash | You | Full price | None to a lender. | Who receives the Shines payment, and that the $20 owner adder per REC is counted. |
| Loan | You | Often $0 | Loan payment, plus your remaining utility bill. | Cash vs financed price. A dealer fee can cancel out the Shines payment. |
| Lease | Solar company | Often $0 | Monthly lease payment, plus your remaining utility bill. | The company keeps the Shines payment, and leases get no $20 adder. Check the escalator and transfer rules. |
| PPA | Solar company | Often $0 | A price per kWh for the power the panels make. | Same as a lease for the Shines payment. Compare the PPA rate with your supply-only export credit. |
For loan terms and a payment calculator, see our solar financing guide. Low-income households can check Illinois Solar for All, a separate program with its own rules.
What an Illinois solar quote should show
Line up two or three quotes. If one cannot answer these, its payback number cannot be checked.
- Shines payment in writing. Block price, estimated total, payment schedule and who receives it.
- Utility and rebate. Your utility’s name, its rebate amount, and who applies for it.
- Export assumptions. The supply-only credit assumed for exports since January 1, 2025.
- Cash and financed prices. Both totals side by side, with any dealer fee shown.
- System size and production. kW, year-one kWh and the shading assumed.
- Vendor status. The installer’s Illinois Shines approved vendor registration.
Compare Illinois solar quotes
Ask each installer to show the Shines payment and your utility’s rebate in writing. Enter your ZIP code to request quotes from solar providers that serve your area.
How EcoGen is paid
EcoGen America does not sell or install solar. When you request quotes, we pass your request to solar providers serving your area, and they pay us for the introduction. Providers can include installers, solar marketplaces and lead exchanges, and more than one may contact you. You never pay us. This is not an application to Illinois Shines.
More Illinois solar guides
- Illinois solar guide: utilities, incentives and installers in one place
- Illinois solar companies: compare local installers before you request quotes
- Illinois solar incentives: Shines, rebates and property tax
- What solar costs in Illinois
- Free solar panels in Illinois: Solar for All vs zero-down offers
- Are solar panels worth it? The national guide and payback calculator
All 51 state guides
Illinois solar questions
Are solar panels worth it in Illinois?
They can be, mostly because of the Illinois Shines payment. In our example a typical owned system pays back in about 5 years when the payment reaches you and about 18 when it does not. Your roof, your utility and the contract decide which case is yours, so ask for both numbers.
Is solar worth it in Illinois without the federal tax credit?
It can be. The homeowner credit does not apply to systems installed after December 31, 2025. In Illinois the Shines payment and the utility rebate now carry most of the incentive value. One quirk: the $20 owner adder per REC is not paid if a federal credit is claimed, so its loss costs less here.
How much difference does the Shines payment make?
For a typical 9.23 kW owned ComEd system, about $18,040 over the contract at 2026-27 prices. That is close to two-thirds of the $28,152 cash price. The amount depends on your utility’s REC group, the block open when your project is submitted and the system’s estimated output.
Does it matter whether I am on ComEd or Ameren?
Yes. The REC price differs by group, so the same system earns about $18,040 in ComEd territory and about $16,180 with Ameren or MidAmerican. Both ComEd and Ameren offer a $300 per kW smart inverter rebate. A quote that models the wrong utility is wrong on both payments.
Is solar worth it in Chicago?
The same Shines and ComEd math applies. City permits and older roofs can add cost and time, so ask what the quote includes for permits, roof work and electrical upgrades. Delays matter in Illinois, because the payment depends on the block that is open when your project is submitted.
Should I wait for better Illinois incentives?
Usually not for the Shines payment. REC prices are set for each program year, and a block can fill before your project is submitted. The better move is a fair cash price from a registered vendor who submits promptly. Waiting can make sense if your roof needs replacing first.
Sources, method and corrections
The example uses the EcoGen Solar Cost Index typical Illinois system (September 2026) and current program prices. Three inputs are our assumptions, not measured values: 40% of the solar power is used at home as it is made and 60% is sent to the grid, exports earn a 10¢ credit (a yearly illustration of ComEd’s supply credit), and owner costs are $277 a year ($30 per kW, including a reserve for a new inverter). Simple payback uses flat first-year values and counts the whole Shines payment at the start. The calculator runs in your browser and sends nothing.
Spotted an error? Tell us through our corrections and feedback process.
- Illinois Shines: 2026-27 REC prices (REC group prices and the $20 owner adder; checked September 29, 2026)
- ComEd: Net metering FAQ (supply-only export credits for new customers since January 1, 2025)
- Ameren Illinois: distributed generation rebate tariff ($300 per kW solar rebate)
- U.S. EIA: average residential electricity price by state (12-month average, August 2025 to July 2026, as used in the Cost Index)
- IRS: FAQs on the 2025 changes to Section 25D (homeowner credit ends for installations after December 31, 2025)
- EcoGen Solar Cost Index, September 2026: what solar costs in Illinois (typical system size, price and electricity price)
