Illinois state reference
Illinois solar, checked against local sources.
Illinois solar math now depends on utility territory, Smart Solar Billing, REC value timing, and the post-25D federal landscape.
- Worked example
- Lake Zurich
- Utilities
- 3
- Focus
- ComEd, Ameren, and Illinois Shines
Utility record
Billing rules before sales math.
Each hub checks the active net-metering rider, export treatment, and incentive layer.
- COMED Commonwealth Edison → Northern Illinois, Chicago metro and surrounding counties
- AMEREN Ameren Illinois → Central and southern Illinois, Springfield, Peoria, and downstate territories
- NAPERVILLE ELECTRIC Naperville Electric Utility → City of Naperville and adjacent unincorporated DuPage parcels served by the municipal utility
Worked example
The sourced example for this state.
Lake Zurich carries the production and payback figures for this state. Towns on the same utility share that tariff, which is documented on the utility pages above.
Reference articles
Policy explainers and buyer-side diagnostics that apply across the state.
- The Federal Solar Credit in 2026 Section 25D expired December 31, 2025 under Public Law 119-21. What that means for cash and loan installs in 2026, what Section 48E still covers for third-party-owned systems, and how to spot a stale-data quote.
- Illinois Solar Buyback Rates Explained How net export compensation works under ComEd Smart Solar Billing versus Ameren, why the headline buyback rate is not the all-in retail rate, and how the January 2025 change reshaped payback math for new installations.
- Solar Quote Questions Worth Asking The questions that make a solar quote easier to judge. P50 versus P90 production estimates, panel-level monitoring access, UCC-1 lien language in financed deals, embedded dealer fees, and what the FTC Holder Rule actually does when an installer fails.
- The "Illinois 25% State Tax Credit" Myth There is no 25% state income-tax credit for solar in Illinois. The Illinois Department of Revenue enumerates 76 individual income-tax credits; zero are for residential solar or photovoltaics. What homeowners are usually being shown when they hear "25%" is the Illinois Shines SREC program structured to look like a credit on a sales worksheet.