Solar payback in Illinois
A 7.7 kW home solar system in Illinois pays for itself in about 14.3 years at 2026 prices, with no federal tax credit. That ranks #19 of 51 states, where 1 is the fastest.
- Installed price
- $3.60/W
- national median, 2025
- Solar output
- 1,308 kWh
- per kW a year, Chicago weather
- Electricity rate
- 19.22¢/kWh
- average home rate, EIA
- Value of a solar kWh
- 19.2¢
- full retail net metering
Pays back in year 15
- Cost up front
- $27,720
- Saved per year
- $1,936
- Ahead after 25 years
- $20,674
Payback by quoted price and roof direction
Find your installer's price per watt (total price divided by system watts) to read your payback in Illinois. Nationally, cash buyers paid a median of $3.00 per watt in 2025 and loan buyers $4.50, because loan fees are often built into the price. East and west roofs make 15% and 15% less power than south here.
| Price per watt | 7.7 kW costs | South roof | East roof | West roof |
|---|---|---|---|---|
| $2.50 | $19,250 | 9.9 years | 11.8 years | 11.7 years |
| $3.00 | $23,100 | 11.9 years | 14.1 years | 14.0 years |
| $3.60 (national median) | $27,720 | 14.3 years | 16.9 years | 16.8 years |
| $4.00 | $30,800 | 15.9 years | 18.8 years | 18.6 years |
| $4.50 | $34,650 | 17.9 years | 21.2 years | 21.0 years |
System size barely changes payback here: a bigger system costs more and saves more in about the same proportion.
Questions about solar in Illinois
How does Illinois pay for solar power I send to the grid?
Illinois is counted here as full retail net metering: each kWh you export earns the same as a kWh you would buy. We have not checked Illinois's rules against its utility commission yet, and some utilities pay less, so check your utility's net metering tariff.
How much did the end of the federal tax credit change payback in Illinois?
With the 30% credit that ended in 2025, the same system would have paid back in about 10.0 years instead of 14.3. The credit ended for systems installed after December 31, 2025. Leased systems and power purchase agreements can still pass on a business credit, but then you do not own the panels.
Is 1,308 kWh per kW a lot?
The range across states runs from about 922 kWh in Alaska to about 1,779 in the Southwest. Sunshine matters less than people expect: the electricity rate and how your utility credits exports move payback more.