The two numbers that matter
Electricity price: 19.2¢/kWh, close to the national state average of 19.3¢. Every kilowatt-hour your panels make replaces one you'd buy at this price, so higher prices mean faster payback.
Sunshine: 4.5 peak sun hours a day, less than the state average of 5.0. Each kW of panels here makes roughly 1,284 kWh a year after real-world losses.
Estimates by bill size
| Monthly bill | Usage | System | Cost | Year-1 savings | Payback | 25-yr net |
|---|---|---|---|---|---|---|
| $100/month | 521 kWh | 4.4 kW | $13,140 | $920 | 13 yrs | $18,150 |
| $150/month | 781 kWh | 6.6 kW | $19,710 | $1,380 | 13 yrs | $27,230 |
| $250/month | 1302 kWh | 11.0 kW | $32,860 | $2,300 | 13 yrs | $45,380 |
Assumes $3.00/W installed, 90% usage offset, no federal tax credit, 3% yearly price rise and 0.5% yearly panel degradation. Sources: US Energy Information Administration (EIA), Electric Power Monthly, residential average price, July 2026; NREL PVWatts / NSRDB, average peak sun hours for each state's largest city.
Incentives in illinois.html
No major statewide solar tax credit as of October 2026. Many states exempt solar from property or sales tax, and some utilities offer rebates. Search DSIRE (dsireusa.org) for your ZIP code.
The US 30% Residential Clean Energy Credit ended for homeowner systems installed after December 31, 2025. Leased systems and PPAs may still be priced with a federal business credit. See solar incentives in 2026.
Plug-in and balcony solar in illinois.html
No dedicated plug-in solar law yet as of October 2026. Ask your utility before connecting anything to an outlet; most require an interconnection application. Over 30 states have considered bills, so check back.
Estimate a kit with the plug-in solar calculator.
Next steps
- Check your actual rate on your bill. Many utilities in illinois.html charge more or less than the state average.
- Run your own numbers in the savings calculator.
- Get at least three quotes and compare the price per watt. Use our quote checklist.
Questions about solar in illinois.html
Is solar worth it in illinois.html?
Fair case. Solar can work, but the margin is thinner. Quote shopping and a cash or low-rate loan matter more.
How much does a solar system cost in illinois.html?
At about $3.00 per watt before incentives, a 6.6 kW system costs roughly $19,710. Local quotes vary with roof, equipment and installer.
How many panels would a illinois.html home need?
For a $150 monthly bill, about 6.6 kW, or roughly 2.3 panels per kW using 430 W panels. Use the system size calculator for your exact usage.