Indiana vs Illinois Solar Incentives: Which State Gets the Better Deal?
Side-by-side comparison of Indiana and Illinois solar incentive programs in 2026: state tax credits, net metering rules, exemptions, payback period, and projected 25-year savings.
| Metric | IN · Indiana | IL · Illinois |
|---|---|---|
| Avg Monthly Bill | $140 | $125 |
| Peak Sun Hours / Day | 4.5 ◆ | 4.4 |
| Avg $/Watt Installed | $2.9 ◆ | $2.95 |
| State Tax Credit | None | None |
| Net Metering | None | retail |
| SREC Market | No | ~$9200 |
| Property Tax Exempt | No | Yes |
| Sales Tax Exempt | No | No |
| Payback, pre-credit model (yrs) | 10.6 | 7 ◆ |
| 25-yr savings, pre-credit model | $26,800 | $40,300 ◆ |
Payback and 25-year savings were modeled while the federal residential credit applied. They are not a 2026 quote. The calculator uses $0 federal credit and state incentives only.
State Tax Credit Comparison
Indiana offers no state income tax credit. Illinois offers no state income tax credit.
Net Metering Policies
Indiana: no statewide net metering mandate. Illinois: retail rate net metering active.
Net metering is often the most economically significant solar policy because it determines how excess production is valued. Retail-rate states (where you receive full retail price for exported energy) have substantially better solar economics than avoided-cost or no-net-metering states.
Average 25-Year Savings
Indiana: $26,800 over 25 years (avg payback 10.6 yrs). Illinois: $40,300 over 25 years (avg payback 7 yrs).
Verdict: Which State Wins on Solar?
Illinois delivers stronger lifetime solar economics than Indiana due to more favorable net metering rules.
Note: state averages mask significant within-state variation. Your specific utility, roof orientation, and household electricity profile drive your actual numbers — use the calculator to model your home directly.