Illinois vs Wisconsin Solar Incentives: Which State Gets the Better Deal?
Side-by-side comparison of Illinois and Wisconsin solar incentive programs in 2026: state tax credits, net metering rules, exemptions, payback period, and projected 25-year savings.
| Metric | IL · Illinois | WI · Wisconsin |
|---|---|---|
| Avg Monthly Bill | $125 | $125 |
| Peak Sun Hours / Day | 4.4 | 4.4 |
| Avg $/Watt Installed | $2.95 | $2.95 |
| State Tax Credit | None | None |
| Net Metering | retail | retail |
| SREC Market | ~$9200 | No |
| Property Tax Exempt | Yes | Yes |
| Sales Tax Exempt | No | Yes |
| Payback, pre-credit model (yrs) | 7 ◆ | 9.2 |
| 25-yr savings, pre-credit model | $40,300 ◆ | $30,100 |
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
Illinois offers no state income tax credit. Wisconsin offers no state income tax credit.
Net Metering Policies
Illinois: retail rate net metering active. Wisconsin: 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
Illinois: $40,300 over 25 years (avg payback 7 yrs). Wisconsin: $30,100 over 25 years (avg payback 9.2 yrs).
Verdict: Which State Wins on Solar?
Illinois edges out Wisconsin on lifetime savings primarily 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.