Solar in Illinois: is it worth it in 2026?
Illinois is a slow-payback state: solar works, but it takes well over a decade to earn back what you paid. Three things decide that: electricity prices rank 17th of 51, its sun ranks 37th, and exported power earns much less than the retail rate. Of the 51 states and DC, Illinois has the 35th-fastest payback for a typical home.
The average home here pays about $127 a month for 716 kWh. A 6 kW system sized for that home would knock about $971 off the first year's bills, 64% of the total.
Checked November 12, 2026
What makes solar pay off in Illinois
- Size the system to what you use during the day, not to your whole year: extra power sent to the grid earns about 50% of the retail rate. A battery, or running the dishwasher, laundry and EV charging while the sun is up, raises the value of every panel.
- The price per watt decides it. At 17.7¢ per kWh, the price per watt matters as much as the sun. At $3.34 per watt, the high end of what companies quote, payback for a typical system here stretches to 20 years.
Payback by system size
An average Illinois home uses about 8,592 kWh a year. Here's how systems sized to cover part or all of that work out, bought with cash at $2.57 per watt:
| Covers | Size | Price | Makes a year | Payback | 25-year savings |
|---|---|---|---|---|---|
| 53% | 3.5 kW | $8,995 | 4,578 kWh | 18 years | $6,489 |
| 76% | 5 kW | $12,850 | 6,540 kWh | 17 years | $10,395 |
| 99% | 6.5 kW | $16,705 | 8,502 kWh | 16 years | $14,301 |
| 122% | 8 kW | $20,560 | 10,464 kWh | 17 years | $14,934 |
The 6.5 kW system pays back fastest, but the 8 kW system saves the most over 25 years, though only if the extra power is used at home. Assumes exported power earns about 50% of the retail rate, prices rise 2.5% a year and one inverter replacement.
How Illinois credits power you send to the grid
Reduced credit (net billing)
Since January 1, 2025, new ComEd, Ameren and MidAmerican customers get credit only for the supply part of the bill (about 8 to 12 cents), not delivery, taxes or fees. A one-time rebate of about $300 per kW of panels helps make up for it.
By utility
- ComEd: Supply-only credits for systems connected since January 1, 2025: roughly 8 to 12 cents per kWh, varying by month.
- Ameren Illinois: Supply-only credits for systems connected since January 1, 2025, roughly 8 to 12 cents per kWh by month, with a distributed generation rebate for new systems.
Before you sign in Illinois
Check the license. Illinois has no statewide license for general contractors or electricians; your city or county licenses them. Ask for the local license and proof of insurance.
Illinois has no solar-specific sales law that we know of, so its general consumer protection law applies.
In every state, the FTC Cooling-Off Rule lets you cancel a contract signed at your home until midnight of the third business day.
How to choose a solar company · Contract checklist · Before you sign
Illinois compared with its neighbors
| State | Electricity | kWh per kW | Typical payback | Exported power |
|---|---|---|---|---|
| Illinois | 17.7¢ | 1,308 | 16 years | Reduced credit (net billing) |
| Wisconsin | 18.1¢ | 1,334 | 14 years | Monthly netting |
| Iowa | 13.6¢ | 1,367 | 14 years | Full credit (net metering) |
| Missouri | 13.3¢ | 1,433 | 15 years | Monthly netting |
| Kentucky | 13.1¢ | 1,343 | 20 years | Reduced credit (net billing) |
| Indiana | 16.0¢ | 1,332 | 19 years | Reduced credit (net billing) |
Questions about solar in Illinois
How long does solar take to pay for itself in Illinois?
About 16 years for a typical 6 kW system bought with cash at the 2026 median price of $2.57 per watt, with no federal tax credit and one inverter replacement. A bigger or smaller system, a different price, or your own usage will change that; the table above shows other sizes.
Does Illinois have net metering?
Not full net metering. Since January 1, 2025, new ComEd, Ameren and MidAmerican customers get credit only for the supply part of the bill (about 8 to 12 cents), not delivery, taxes or fees. A one-time rebate of about $300 per kW of panels helps make up for it.
Is there a solar tax credit in Illinois in 2026?
Not from the federal government for buyers: the 30% homeowner credit ended for systems installed after December 31, 2025. For a typical 6 kW system in Illinois, that credit was worth about $4,626 and brought payback down to 11 years, instead of 16 years now. Leasing companies can still claim a business credit, so ask for a lease or PPA price too. Your state energy office lists any state rebates.
Is a solar battery worth it in Illinois?
On bill savings alone, not quite: a 13.5 kWh battery at about $15,650 would move about 3,548 kWh of solar power a year from the grid to your evenings in a typical Illinois home, adding about $4,314 of savings over 15 years. That doesn't cover its price, so the system's payback goes from 16 years to 24 years; the rest is paying for backup during outages. Time-of-use rates, battery rebates and utility payments for sharing your battery can tip it; try your numbers in the payback calculator.
Is plug-in solar legal in Illinois?
Not yet. A bill (HB 4371 / SB 3104) is pending: stalled; lawmakers return in november.
How do I check a solar company's license in Illinois?
Illinois has no statewide license for general contractors or electricians; your city or county licenses them. Ask for the local license and proof of insurance.
More guides: What changed for solar in 2026 · Lease or buy? · Plug-in solar · Is my solar system working?
Sources: U.S. Energy Information Administration (EIA), final 2025 data: Annual State Historical Spreadsheets (Form EIA-861, released October 7, 2026) and Electric Power Annual (October 21, 2026); NREL PVWatts (National Solar Radiation Database), statewide averages; Illinois Shines: changes to net metering; Solar.com: Plug-in solar, the 2026 guide; EnergySage: median quoted price, first half of 2026.