The short answer
New residential and small commercial customers in ComEd, Ameren and MidAmerican territories moved to supply-only net metering from January 1, 2025, under program guidance. Legacy full-retail arrangements require separate eligibility review.
The decision this guide helps you make
Separate self-consumed solar energy from exported energy. The avoided charges and export credit may differ, so valuing every generated kWh at the whole retail bill can overstate savings.
Evidence to gather before deciding
Confirm the interconnection and net-metering enrollment dates, customer class, applicable tariff, rebate election and interval usage with the utility.
The detail that is easy to miss
Illinois Shines notes continuing treatment for eligible systems registered for full-retail net metering before 2025. Do not apply an old full-retail example to a new system without checking the actual arrangement.
Value self-use and exports separately
Decision case · figures, where used, are hypothetical
For illustrative production of 1,000 kWh with 600 used on site and 400 exported, apply the relevant avoided cost to 600 and actual export-credit rules to 400. Valuing all output at a historical whole-bill rate can overstate value.
What would make this decision ready?
Confirm class, interconnection timing and legacy status. Illinois Shines describes the 2025 change for new residential and small-commercial accounts at named utilities. Keep incentives separate from bill credits.
Separate generation, credits and payments
Solar economics involve when power is produced and consumed, how exports are credited, what the subscriber or owner pays, and who owns renewable attributes. A generation estimate is not automatically a bill saving. Request a month-by-month illustration and reconcile it with utility billing and any provider invoice. Identify estimated output, degradation, production guarantees and fees separately.
Apply current rules to the right installation
Illinois Shines explains the January 1, 2025 move to supply-only net metering for new residential and small-commercial customers in ComEd, Ameren and MidAmerican territories, alongside legacy treatment for qualifying earlier systems. The actual utility tariff, enrollment and rebate choices still matter. Municipal utilities have their own arrangements. Do not use a legacy full-retail credit on a new project simply because an older article did so.
Keep incentives out of the base case until verified
Federal tax treatment, Illinois program payments and utility rebates are separate. The IRS currently states that the residential clean energy credit is unavailable for property placed in service after December 31, 2025. A historical residential credit example is not a current business tax opinion. Confirm program year, project status, ownership, tax eligibility and payment timing with the appropriate administrator or qualified tax adviser.
Compare benefits you can substantiate
For a subscription, subtract the subscription payment and applicable fees from the value of utility credits. For an owned system, separate self-consumption, export credits, capital cost, maintenance, financing and attribute payments. A battery adds backup and load-shifting possibilities but also cost, losses and capacity limits. Model uncertain benefits as scenarios rather than promising that solar or storage guarantees lower bills.
| Record | Why it matters | How to verify |
|---|---|---|
| Account and scope | Keeps the decision tied to the right service and customer. | Use the current utility, meter and customer class; keep account identifiers private. |
| Period and units | Prevents comparisons across different months or measures. | Write down billing days and whether the amount is kWh, kW, therms or dollars. |
| Written terms | Distinguishes a claim from an obligation. | Save the full proposed agreement, tariff or program notice and its date. |
| Unknowns and exclusions | Shows what the estimate cannot establish. | List unresolved charges, eligibility and operating assumptions before deciding. |
Use a tool without sending your numbers
A calculator is useful for checking an assumption, not for confirming a tariff, incentive or legal interpretation. Enter only nonidentifying figures in the relevant worksheet. If you need a human review, describe the question and utility first; do not paste an account number or confidential document into the inquiry. Keep the model alongside the written terms so an apparently precise output is not mistaken for a complete quote.
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Sources & further checks
Primary references checked for this guide on October 15, 2026. Follow the source for current tariffs, eligibility and program terms; rates here are not live offers.