- Bloomingtonsame day
- Bolingbrook16.5 business days
- Buffalo Grove8 business days
- Des Plaines17 business days
- East Peoria7 business days
- Elmhurst17 business days
- Evanston13.5 business days
- Glendale Heights25 business days
- Jacksonville4 business days
- Mahometsame day
- Morton1 business day
- Mount Prospect4 business days
- Mundelein8 business days
- Northbrook12 business days
- Oak Lawn9 business days
- Pekin7 business days
- Waukegan11 business days
Illinois utility interconnection
| Utility | Approval before install | Apply via | Fee | Utility response | System size cap | Capacity map |
|---|---|---|---|---|---|---|
| City of Naperville - (IL) | Required | In Person | No fee | 10 days (voluntary) | 120% of annual usage | Not on record |
| Commonwealth Edison Co (ComEd) | Required | Portal | Online payment | 10 days (required by rule) | 110% of annual usage | Yes |
Source: SolarTRACE, National Renewable Energy Laboratory (NREL), 2025-09-09 release. Times are medians for residential solar in the year shown. Requirements change — confirm current rules, fees and forms with the jurisdiction before you submit.