Solar in Illinois: how the rules work
How Illinois credits the power solar panels send back to the grid, what homes there pay for electricity, and what to check when a home with solar is bought or sold.
How exported power is credited
Power sent to the grid is credited at a set share of the retail rate, below what the home pays for power it buys.
Systems energized on/after Jan 1, 2025 get supply-only credits (energy supply/transmission, not delivery), roughly 40-55% of the full retail rate depending on the bill. Pre-2025 systems are grandfathered at full 1:1 retail unless they re-interconnect (e.g., add a battery or increase AC size). New customers can receive a one-time DG rebate. The Clean and Reliable Grid Affordability Act (SB 25, signed Jan 9, 2026) did not change solar export crediting; it extends net metering to behind-the-meter battery storage.
What changes for a home with solar
A savings estimate that assumes full retail credit for exported power overstates the value of that power for systems on the current rules. Power used in the home still offsets the full retail rate.
Older systems are often grandfathered on earlier, better terms for a set number of years. Which rules a particular system is on depends on its interconnection date, stated in the note above.
Electricity here costs about 19.2¢ per kWh (2026) and has risen about 2.9% a year over the last decade. A lease or PPA escalator above that pace makes the solar payment rise faster than utility rates have.
When a home with solar is sold in Illinois
- Owned outright: proof it is paid off, the warranties, and the utility’s interconnection or net-metering agreement, which has to move into the buyer’s name.
- Loan: a payoff letter, and whether the buyer can assume the loan. Many solar loans are secured by a UCC-1 fixture filing that title will find.
- Lease or PPA: the transfer process and how long approval takes, the buyer’s credit check, the current payment or rate and its yearly increase, and a buyout quote.
- Every case: whether the export-credit terms above stay with the home after the sale, and the last 12 months of production from the monitoring app.
Have the solar contract for a Illinois home?
Upload it and get a letter-graded report card: price, production, payment changes, value and transfer terms, measured against Illinois’s rates and rules.
Grade a solar contractSources
- www.citizensutilityboard.org/wp-content/uploads/2025/06/Net-Metering-Pre2025.pdf (2025-06)
- www.solarinsure.com/net-metering-2-0-arrives-in-illinois
- www.stlpr.org/health-science-environment/2026-01-09/pritzker-signs-major-energy-bill-proje (2026-01-09)
- Electricity prices: EIA Electric Power Monthly, Table 5.6.B (2026) and EIA state annual averages 2014–2024
- Installed price: EnergySage marketplace, September 2026