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Illinois vs Oklahoma Solar Comparison

Oklahoma gets more sun (5.1 hrs/day) while Illinois has the faster payback (9 years).Illinois offers higher 20-year savings at $32,600.

Illinois

4.0 hrs

9yr payback

$32,600

20yr savings

Oklahoma

5.1 hrs

10.5yr payback

$28,400

20yr savings

Side-by-Side Comparison

MetricIllinoisOklahoma
Peak Sun Hours4.0 hrs5.1 hrs
Cost per Watt$3.15$2.95
6kW System Cost$18,900$17,700
Federal Tax Credit30%30%
State Tax CreditNoneNone
State RebateNoneNone
Net MeteringFull Net MeteringPartial Net Metering
Electricity Rate16.27¢/kWh12.82¢/kWh
Payback Period9 years10.5 years
20-Year Savings$32,600$28,400

Verdict

Illinois is the better state for solar ROI with $32,600 in 20-year savings and a 9-year payback period. Oklahoma has more sun exposure at 5.1 hrs/day, making it ideal for maximum energy production. Both states qualify for the 30% federal solar tax credit.

Frequently Asked Questions

Is solar better in Illinois or Oklahoma?

Oklahoma gets more sun (5.1 peak hours/day vs 4). Illinois has a faster payback (9 years) and Illinois offers higher 20-year savings ($32,600).

How do solar costs compare between Illinois and Oklahoma?

A 6kW system costs $18,900 in Illinois vs $17,700 in Oklahoma before incentives. Both qualify for the 30% federal tax credit.

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Data verified March 2026 · Source: NREL, DSIRE, EIA