Illinois Solar Guide 2026
Everything Illinois homeowners need to know: costs, incentives, net metering policy, and what makes this state unique for solar.
Quick answer
Illinois solar economics depend mainly on 4.4 average peak sun hours, an estimated $3/W installed cost, 15.0¢/kWh electricity, and the state's current net-metering rules.
Reviewed 2026-07-26
- Best for
- Illinois homeowners comparing solar costs, incentives, and payback assumptions.
- Inputs needed
- annual kWh usage, utility rate, installed $/W, net-metering policy
- Formula used
- Typical production = system kW × peak sun hours × 365.
- Source checked
- state incentive data, utility tariff checks, Wattcrunch price benchmarks
Key fact about Illinois solar
Illinois Shines SREC program significantly boosts solar ROI — SRECs can add thousands of dollars in value over 15 years. Combined with full retail net metering, Illinois is one of the better Midwest states for solar.
Peak sun hours
4.4
hrs/day avg
Avg electricity rate
15.0¢
per kWh
Median install cost
$3/W
before incentives
Typical payback
9 yrs
8 kW system, avg usage
Typical 8 kW system in Illinois
Annual production
12,848 kWh
Year-1 savings
$1,927
System cost (est.)
$24,000
No federal tax credit — Section 25D expired December 31, 2025.
Illinois Net Metering Policy
Full retail net metering
Illinois mandates full retail net metering under the Illinois Power Agency Act. ComEd and Ameren customers get retail-rate credit for exports. The Illinois Shines SREC program provides a substantial additional incentive.
Illinois Solar Incentives
Available in addition to any utility rebates. Federal 25D credit is $0 for homeowner-owned systems from 2026.
- ✓Illinois Shines SREC program (significant value — check IPA portal)
- ✓Illinois Solar for All (low-income)
- ✓Property tax freeze for solar
Top Utilities in Illinois
Interconnection timeline: 4–10 weeks
State-specific decision guide
What to verify before signing a Illinois solar quote
In Illinois, the financial result depends on more than sunshine or the headline installation price. Confirm the export rule, program eligibility date, and interconnection timeline for your exact utility before treating a payback estimate as a promise.
Export value
This page models full retail net metering. Ask which tariff and export credit apply to your account, not only which program name appears in the proposal.
Incentive eligibility
Check equipment, income, installer, application, and placed-in-service rules before subtracting an incentive from the quote. Programs can close or change terms.
Interconnection
Budget for the published 4–10 weeks and confirm who pays for a required meter, service upgrade, or engineering review.
Source trail: production assumptions use NREL PVWatts; incentive discovery should be checked against DSIRE; electricity-market context is available from the EIA. Confirm final tax treatment with the IRS and your utility.
Calculate your Illinois solar economics
Our calculators are pre-filled with Illinois data. Run any tool below.