State solar guide
Illinois has strong solar fundamentals in 2026. The federal residential credit expired December 31, 2025, but state incentives and net-metering rules still support solid payback timelines for qualified homeowners.
Sources: ElectricChoice June 2026 | NREL PVWatts (statewide range; Chicago area approximately 4.51 peak sun hours per day) | EnergySage May 2026 | Federal residential credit: Section 25D expired December 31, 2025, H.R.1 (One Big Beautiful Bill Act).
Net metering
Illinois transitioned new installations to supply-only net metering (Smart Solar Billing) effective January 1, 2025. Export credits apply only to the supply and transmission component of the bill, not delivery charges, materially reducing bill savings compared to full retail net metering. Systems installed before January 1, 2025 are grandfathered into full retail net metering for the life of the system.
ComEd and Ameren Illinois each administer separate Smart Solar Billing tariffs. Contact your utility for the current supply rate component, which is the portion credited for exports. Battery storage becomes more valuable under supply-only treatment because self-consumed solar still avoids the full retail rate.
Program: Smart Solar Billing (supply-only net metering). Last verified: June 2, 2026. DSIRE source (opens in new tab).
Verify with your utility
Net-metering rules change by utility and program cycle. Confirm current export credit rates and eligibility with your specific Illinois utility before contracting. Current program details at DSIRE (opens in new tab).
State incentive stack
The federal residential credit expired December 31, 2025. The programs below are what remains for Illinois homeowners. Amounts and availability change; every program is date-stamped and linked to its DSIRE source.
Federal residential solar credit (Section 25D): expired. The Section 25D residential investment tax credit expired December 31, 2025. The residential credit rate is 0%. State and local incentives below may still significantly reduce your net system cost. Commercial systems still qualify for Section 48E (30%).
| Program | Benefit | Eligibility | Status | Source |
|---|---|---|---|---|
| ComEd Utility rebate / export credit active | See description (as of 2026-06-02) Distributed Generation rebate: $300 per kW for solar, $300 per kWh for battery storage | ComEd customers. Verify eligibility directly with your utility. | Active | DSIRE (opens in new tab) |
| Ameren Illinois Utility rebate / export credit active | See description (as of 2026-06-02) Distributed Generation rebate program similar to ComEd | Ameren Illinois customers. Verify eligibility directly with your utility. | Active | DSIRE (opens in new tab) |
| Illinois Solar Property Tax Exemption Property tax exemption Confirm exemption filing requirements with your county assessor. | Exemption on solar-added home value (amount varies by local tax rate and system size) Illinois exempts solar energy system added value from property tax assessment statewide under 35 ILCS 200/10-10. Estimated savings $200 to $500 per year depending on county tax rate. | Illinois residential property owners with qualifying solar installations. | Active | DSIRE (opens in new tab) |
Data last verified June 2, 2026. Incentive programs change; verify current amounts and availability at dsireusa.org (opens in new tab) before committing to a project.
Battery storage incentives in Illinois
ComEd offers a Distributed Generation battery storage rebate of $300 per kWh of installed battery capacity for eligible residential customers in its territory. Ameren Illinois offers a similar DG rebate program. Battery storage is especially valuable under Illinois supply-only Smart Solar Billing, where self-consumed solar avoids the full retail rate while exports earn only the supply component. Source: ComEd DG rebate program documentation, June 2026.
Savings example
This example uses real Illinois market data. No federal residential credit is applied. Figures are illustrative; your in-home assessment uses your actual utility bills and the current rate schedule for your specific utility.
Annual production estimated at approximately 10,800 kWh for a 9 kW system at 4.51 peak sun hours. Assumes 75 percent self-consumption at 17.83 cents per kWh retail value; remaining 25 percent exported at the supply-only rate (approximately 9 to 10 cents per kWh, well below full retail). Utility rate escalation at 3 percent annually. Illinois Shines REC payment included as upfront cost reduction; if system is on waitlist, payback extends significantly. Federal residential credit: $0 (expired). Figures are illustrative; your in-home assessment will use your actual bills and current block pricing.
Illinois homeowner savings example (illustrative)
Illustrative example. Federal residential credit: $0 (Section 25D expired December 31, 2025). Your estimate will use your actual utility bills and current rate schedule.
Permitting
Illinois does not have a statewide solar permit fee cap equivalent to California AB 1124. Permit timelines vary by municipality and county. Major metro areas (Chicago, Aurora, Rockford, Springfield) typically require 2 to 6 weeks for residential solar permit approval. SolarAPP+ adoption in Illinois is limited; most jurisdictions use manual review. Contract to energization typically runs 8 to 16 weeks statewide.
Chicago Building Department and suburban Cook County AHJs each maintain separate queues and fees. Downstate municipalities generally process permits faster than Chicagoland. Verify current AHJ timelines with your installer before signing a contract.
Commercial solar in Illinois
The commercial solar credit (Section 48E, 30 percent) remains available for qualifying commercial projects. Construction must begin by July 4, 2026 to qualify for the full placed-in-service window. Combined with MACRS accelerated depreciation and 100 percent first-year bonus depreciation, the combined first-year federal benefit can reach 45 to 55 percent of project cost for many Illinois business owners. Direct Pay is also available for nonprofits, municipalities, and other tax-exempt entities.
Commercial solar overviewCommercial solar projects must begin construction by July 4, 2026 to qualify for the 30 percent Section 48E federal tax credit. After that date, the system must be placed in service by December 31, 2027.
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