Solar in O'Fallon, IL
With Ameren Illinois's electricity at about 19.1¢ per kWh and 1,390 kWh of sun per kW, solar is worth it for a typical O'Fallon home today: about a 11.6-year payback.
- Payback, typical home
- 11.6 yrsIllinois: 13.5 yrs
- 25-year net
- $39,308after paying $23,260
- Sun
- 1,390kWh per kW per year
- Electricity
- 19.1¢6% above U.S. average
A typical O'Fallon home, by the numbers
| Utility | Ameren Illinois |
|---|---|
| Electricity use | 882 kWh a month |
| Best-value system | 7.6 kW, about 18 panels, 10,562 kWh a year (100% of use) |
| Cost | $25,540, or $23,260 after state incentives |
| First-year savings | $1,885 |
| Payback | 11.6 years |
| Exported power | 10¢/kWh (Ameren Illinois) |
Cash purchase, no federal credit, 3.5% yearly rate increases. Run it with your own numbers.
Homes in O'Fallon
- Owner-occupied homes
- 70%
- Single-family detached
- 67%
- Median home value
- $296k
- Median year built
- 1997
- Population
- 32,262
- Roofs suitable for solar†
- 81%
Census ACS 2020–2024. †Share of 1,327 buildings Google Project Sunroof rated technically suitable (2019 snapshot).
Installers working in O'Fallon
Public installation records for Illinois don't name installers, so we can't rank local companies here. Browse installers in Illinois.
Always verify the license and get at least three quotes. Compare quotes side by side.
Questions about solar in O'Fallon
Is solar worth it in O'Fallon, IL?
For a typical home in O'Fallon, solar is worth it at 2026 prices: a 7.6 kW system costs about $23,260 after state incentives, saves about $1,885 in year one and pays back in about 11.6 years. Enter your address for an estimate based on your roof and bill.
How much solar power does a system produce in O'Fallon?
About 1,390 kWh per year for each kW of panels on a south-facing roof, based on PVWatts and local weather. That's 4% more than the Illinois average. East- or west-facing roofs produce roughly 10–20% less.
Who is the electric utility in O'Fallon?
Most homes in O'Fallon are served by Ameren Illinois, at about 19.1¢ per kWh on average.
How much do solar panels cost in O'Fallon?
A fair cash price is around $3.40 per watt before incentives, so about $25,540 for a 7.6 kW system. There's no federal tax credit for homeowners who buy in 2026.
Nearby
- Belleville 11.6 yrs
- Edwardsville 11.7 yrs
- Granite City 11.7 yrs
- Alton 11.6 yrs
- Springfield 16.5 yrs
- Decatur 11.8 yrs
- Quincy 11.7 yrs
- Pekin 11.7 yrs
- All of Illinois
Data: PVWatts (National Laboratory of the Rockies), EIA-861 2025 adjusted to 2026, U.S. Census ACS, LBNL Tracking the Sun, state policy research as of October 2026.