Topic · Illinois utility billing
Illinois solar buyback rates after January 2025
One of the quieter changes to Illinois solar economics happened on January 1, 2025. The structure that credited a homeowner for power sent back to the grid at the same rate they paid for power drawn from it — sometimes called "1-to-1" credit — ended for systems newly granted permission to operate after that date. The replacement structure pays the homeowner only on the supply portion of their bill, which is materially less per kilowatt-hour.
The new structure: Smart Solar Billing
Under Smart Solar Billing, when your panels send power to the grid you receive a credit at the supply rate only — not the all-in residential rate that also includes transmission and delivery. For ComEd customers, the supply portion is the Price to Compare; for Ameren, it's the supply charge on their tariff.
| Utility | Export credit rate | Old full-retail rate |
|---|---|---|
| ComEd | ~$0.096/kWh (supply only) | ~$0.143/kWh |
| Ameren Illinois | ~$0.08/kWh (supply only) | ~$0.145/kWh |
| MidAmerican | Supply only | Previously matched the all-in residential rate |
Effective rates updated as utility tariffs change. Verify the current ComEd Price to Compare and Ameren supply rate at the time of your install.
What this means for system payback
For a typical 7 kW system that produces about 9,300 kWh per year, the difference between the old and new structures is significant. If half of annual production gets exported (a reasonable approximation for a well-sized system), the credit value falls from roughly $660 per year under the old structure to roughly $325 per year under Smart Solar Billing.
That changes payback periods by 1 to 2 years for a cash-paid system, and more for financed systems where the principal carries interest.
Who is grandfathered in
Systems that received Permission to Operate from their utility on or before December 31, 2024 are grandfathered under the old structure for the system's operational life. If you bought a home with an existing solar array installed before that date, that home retains the old full-retail credit.
Systems that received PTO on or after January 1, 2025 fall under Smart Solar Billing. The date of signed contract or installation does not matter — what matters is the date the utility issued PTO.
What the Smart Inverter Rebate does to partially compensate
Around the same time the export credit structure changed, ComEd and Ameren introduced a Smart Inverter Rebate — a one-time payment of $300 per kW of installed solar capacity, plus $300 per kWh of paired battery storage. For a 7 kW system, that's $2,100 of up-front cost reduction. It does not fully replace the long-tail value of the old export credit, but it is meaningful.
If your quote uses old credit math
Many competitor solar publisher sites still describe Illinois export credit as if it matched the all-in residential rate. SolarReviews, in particular, was still publishing this verbatim on its Illinois incentives page when this topic was last verified. If a solar quote you've been handed assumes a one-to-one credit value, ask the installer to redo the export-credit math at the current Price to Compare. The payback period will be longer than the original quote suggests.
Sources
- Illinois Shines, Smart Solar Billing Credit overview. Source: illinoisshines.com/net-metering-credits · accessed 2026-05-13
- Citizens Utility Board, 2026 ComEd Rates Report. Source: citizensutilityboard.org/blog/2026/01/19 · accessed 2026-05-13
- Illinois Power Agency, Adjustable Block Program documentation. Source: ipa.illinois.gov · accessed 2026-05-13