Solar payback in Illinois (2026)
In Illinois, a typical 8 kW home-solar system costing about $24,000 ($3/W, no federal credit in 2026) has an estimated simple payback of 11.7 years and roughly $37,210 in net savings over 25 years. This assumes an average rate of 18.86¢/kWh and ~1,190 kWh produced per kW each year.
Source: EIA & NREL. Data as of March–June 2026.
Illinois offsets modest sun with the Illinois Shines (adjustable block) SREC program and full retail net metering, which together shorten payback despite average rates.
Illinois solar payback at a glance
| Metric | Value (IL) |
|---|---|
| Average residential rate | 18.86 ¢/kWh |
| Peak sun hours (daily avg) | 4.0 h |
| Production factor | 1,190 kWh/kW/yr |
| 8 kW system annual output | 9,520 kWh |
| Est. up-front cost (8 kW @ $3/W) | $24,000 |
| Year-1 bill savings | $1,795 |
| Estimated simple payback | 11.7 years |
| Estimated 25-year net savings | $37,210 |
Source: EIA Electric Power Monthly (Mar 2026) & NREL PVWatts. Data as of June 2026.
Run your own numbers for Illinois
The calculator below is pre-filled with Illinois's electricity rate and production factor. Change the system size, cost per watt or escalation to match your own quote.
Figures are planning estimates that ignore financing, inverter replacement and maintenance. They assume cash purchase, 3%/yr rate escalation and 0.5%/yr panel degradation. See the methodology and disclaimer.
How Illinois compares
Browse all states to compare payback, or read the guides: Is solar worth it in 2026 without the federal credit? and solar payback period explained.
Frequently asked questions
What is the solar payback period in Illinois?
For a typical 8 kW system costing about $24,000 ($3/W) with no federal tax credit in 2026, the estimated simple payback in Illinois is roughly 11.7 years, based on an average residential rate of 18.86¢/kWh and a production factor of about 1,190 kWh per kW per year. Your actual payback depends on your quote, usage and net-metering rules.
Is solar worth it in Illinois now that the federal tax credit has expired?
The 30% federal residential credit (Section 25D) expired on December 31, 2025, which raises the up-front cost of 2026 installs by about 30%. Illinois offsets modest sun with the Illinois Shines (adjustable block) SREC program and full retail net metering, which together shorten payback despite average rates.
How much electricity does an 8 kW system produce in Illinois?
About 9,520 kWh in year one (8 kW × 1,190 kWh/kW), declining slowly as panels degrade ~0.5% per year.
Other states
Last updated: 2026-06-14