Ameren Illinois solar: net metering and export credit rules

The rules

What happens to the solar power you send to the grid

Ameren Illinois is a delivery only utility that delivers electricity to about 1.2 million customers in more than 1,200 Illinois communities across a 43,700 square mile service territory.

Rider NMOS, Net Metering for On Site Generation

How Ameren Illinois credits exports

Ameren Illinois credits home solar under Rider NMOS, Net Metering for On Site Generation, its net metering tariff on file with the Illinois Commerce Commission under 220 ILCS 5/16-107.5.
For customers who began net metering on or after January 1, 2025 and do not buy supply on a time of use rate, supply and transmission charges are billed on the net of what the home draws and what it sends back each billing period, while delivery and other charges apply to all the electricity the home pulls from the grid.
When the home sends back more than it uses in a billing period, the excess becomes either a kilowatt hour credit or a monetary credit based on the current supply pricing of Ameren or the customer's retail electric supplier, a one time choice made when applying that Ameren says cannot be changed later.
These newer credits carry forward from bill to bill and are not subject to expiration at the end of the annual period.
Customers already net metering on December 31, 2024 stay on the older method, which also credits delivery charges, for 30 years from their permission to operate date, as long as the system's nameplate size does not grow by more than 100 percent and they did not take a rebate on the generator.
Under that older method, unused credits expire at the end of the customer's annual period, which ends with the April or October billing period chosen when applying.

The rule behind it

Illinois Public Utilities Act, net electricity metering, 220 ILCS 5/16-107.5

The program

Rider NMOS, Net Metering for On Site Generation, Rider NMOS

Recent changes

Starting January 1, 2025, new Ameren Illinois net metering customers are credited only against supply and transmission charges, with credits that no longer expire at the end of the annual period. Public Act 104-0458 took effect June 1, 2026, and Ameren's revised Rider NMOS, effective August 14, 2026, lets standalone batteries and vehicle storage systems on a time of use rate take net metering.

Before you connect

Limits, and the steps to get connected

Limits and eligibility

Rider NMOS is open to customers whose solar or other eligible renewable system is on their premises and intended primarily to offset their own current or future electricity use, and the tariff says Ameren will not require a future use estimate in the application or tie continued eligibility to one.
Home systems that are lab certified, inverter based and export 25 kW or less are reviewed under the Level 1 interconnection process in 83 Ill. Adm. Code 466.80.
Since the tariff update effective August 14, 2026, a standalone battery or vehicle storage system energized after June 1, 2026 with a nameplate capacity of 5,000 kW or less can take service under Rider NMOS, and a standalone battery on the customer's side of the meter must be on a time of use rate.
A customer who was net metering before 2025 keeps the older crediting method only if the system's nameplate size does not increase by more than 100 percent after January 1, 2025.

How a home gets connected

An installer certified under 83 Ill. Adm. Code 468, or the homeowner if self installing, submits the interconnection application and the net metering application to Ameren Illinois through its PowerClerk portal, and Ameren sends status updates by email.
In the net metering application, a customer who does not buy supply on hourly pricing chooses between the kilowatt hour credit and the monetary credit.
Ameren tells customers to contact their municipality to find out whether a final inspection is required for the solar system.
After installation, the customer submits a Certificate of Completion under 83 Ill. Adm. Code 466, and the system may not operate until Ameren has approved the interconnection application and returned a signed Certificate of Completion.
Ameren issues permission to operate after the system is deemed to have passed the witness test in 83 Ill. Adm. Code 466.60, and Rider NMOS requires a meter that measures electricity flowing in both directions, which Ameren or a meter service provider arranges if the existing meter cannot.

Federal tax credit

The residential solar credit (section 25D) ended for systems completed after 2025. What that means in 2026.

Questions

Common questions about Ameren Illinois and solar

Does Ameren Illinois still offer net metering for new solar customers?

Yes. Ameren Illinois still offers net metering under Rider NMOS, but for applications after January 1, 2025, extra solar power is credited only against supply and transmission charges, while delivery charges are billed on all the electricity the home pulls from the grid. When applying, the customer picks either a kilowatt hour credit or a monetary credit, and Ameren says that choice cannot be changed later.

Do Ameren Illinois solar credits expire?

For customers who began net metering on or after January 1, 2025, Rider NMOS says leftover credits carry forward and are not subject to expiration at the end of the annual period. If the home changes owners, remaining credits move to the new account at the same address when that account uses the same type of net metering, but they expire if no new account is opened within one year after the old one closes. Customers still on the older pre 2025 method lose unused credits at the end of their annual period.

Can a home battery get net metering with Ameren Illinois?

Rider NMOS lets a solar system include a battery on the customer's side of the meter, and Ameren asks that battery storage be approved by Ameren Illinois to operate with the solar equipment. Since the tariff update effective August 14, 2026, a standalone battery, or an electric vehicle able to work as one, energized after June 1, 2026 can also take net metering. A standalone battery behind the customer's meter must be on a time of use rate to qualify.

Is there still a federal tax credit for home solar?

The federal residential clean energy credit, section 25D, ended for home solar expenditures made after December 31, 2025, under the law signed July 4, 2025. The IRS treats the expenditure as made when installation is completed, so a system completed in 2026 does not qualify even if it was paid for earlier.

Does the consultation cost anything?

No. The consultation is free for homeowners, and there is no obligation to buy anything.

Who will contact me?

Our team confirms a few details with you, then one local solar company for your area contacts you to set up the visit. Your request never goes to a list.

Sources (checked September 26, 2026)

Tariffs and programs change, so confirm current terms with Ameren Illinois before you decide.

Answers homeowners look for

Is the federal solar tax credit still available in 2026?No, not for a home solar system completed in 2026.Can an HOA stop you from installing solar panels?Illinois: State law limits HOA bans Do solar panels raise your property taxes?Illinois: Exemption in state law

How Ameren Illinois credits home solar

Check your home