Solar on an Illinois Co-op or City Utility in 2026: Your 25 kW Right, the Insurance Rule That Ended, and the Lease Catch

If a co-op or a city-owned utility powers your Illinois home, you have a legal right to put solar on it. Since June 1, 2026, state law says that right covers home and small business systems up to and including 25 kW AC. Your utility also can't make you add it to your homeowners insurance if your installer is licensed and carries $1 million / $2 million in liability coverage. What the law still doesn't guarantee is how much your utility credits the power you send back, or whether a lease qualifies. Those two things decide whether solar pays off for you.

I sell solar across central and southern Illinois, and a good share of the homes I see aren't on Ameren at all. They're on a rural electric cooperative, or on a city system like CWLP in Springfield. Most solar guides online are written for ComEd and Ameren customers. Their numbers don't apply to you, and some of their advice is flat wrong for your bill. Here's what does apply.

The key facts

Are you actually on a co-op or city utility?

Check the name printed at the top of your electric bill, not your mailing address. I see this mix-up all the time out in the country. A farmhouse with a small-town mailing address can be on a co-op line while the house across the road is on Ameren.

If the bill says something like "Electric Cooperative," you're a co-op member. If it says City of Peru, CWLP, City of Naperville, City of Highland or a similar town name, you're on a municipal system. Either way, everything below applies to you. ComEd and Ameren customers can stop here and read our net metering changes guide instead.

What changed on June 1, 2026

The Clean and Reliable Grid Affordability Act (Public Act 104-0458) was signed January 8, 2026 and took effect June 1, 2026. Buried in it are two changes to the section of law that governs co-op and city utility solar.

The 25 kW guarantee. Before June, the law set no size floor, so each co-op and city could pick its own cap. Now the law says residential and small commercial customers can interconnect systems "sized up to and including 25 kW AC." For perspective, our how many solar panels do I need guide puts a 10,000 kWh-a-year Springfield home at about 7.2 kW. So 25 kW is plenty of room. It matters most for farms, shops and big all-electric houses.

The insurance demand is gone. Some co-op and city policies asked solar customers to list the utility as an "additional insured" on their homeowners policy, which meant a call to your insurer before you could connect. The new rule flips it. As long as the system meets the safety standards in your interconnection agreement, and your installer is licensed with at least $1 million per occurrence and $2 million aggregate in general liability coverage, the utility can't require it.

Utilities are updating. Illinois Electric Cooperative revised its interconnection policy on May 11, 2026, and it now says members "shall not be required" to name the co-op as an additional insured when those conditions are met. Paperwork lags, though. The City of Peru adopted new solar policies on April 20, 2026 specifically to comply with the new law, and its application form still says customers should name the city as an additional insured "whenever possible." Under the statute, that's a request you don't have to meet if your installer's coverage qualifies.

My advice: get a certificate of insurance from your installer showing those limits and attach it to your application. It ends the conversation before it starts. (For your own policy, our homeowners insurance and solar guide covers what to ask.)

What the law still leaves up to your utility

Here's the part most people miss. The right to connect is guaranteed. The value of what you send back isn't.

The statute lets co-op and city policies on credits "reasonably differ" from what ComEd and Ameren must do. That leaves room for very different deals from one town to the next. Three real examples from 2026 policies show the range:

Springfield is the friendliest of the three by a wide margin. Credit at the full retail rate means every kWh you export is worth what you'd pay for one. Peru and Illinois Electric credit exports closer to what the utility pays for power, which is usually less. In those towns the math rewards a system sized to what you use during the day, not one built to spin the meter backward.

Peru's and Illinois Electric's policies both say solar credits can't be applied to fixed or other non-kWh charges, and CWLP's credit works in kWh too. Plan on still getting a small bill.

What it looks like in Springfield

CWLP is unusually straightforward about how to estimate, so let's use its own numbers. CWLP says it's reasonable to figure about 12 cents per kWh, with no more than 2% a year of rate growth.

A 6 kW system in Springfield makes roughly 8,400 kWh a year, using the PVWatts figure of 1,394 kWh per kW from our panel-count guide. If that system is sized to your yearly use and no credits expire unused in March, that's an estimated $1,000 a year in bill value. That's an estimate, not a promise, and your own usage and roof will move it.

Two honest caveats. First, CWLP's rates have historically run below the Illinois average, which stretches the payback compared with an Ameren home. CWLP's own example: in January 2024, its average customer paid $109.40 for 953 kWh while the average Illinois utility customer paid $142.28. Second, Springfield homes don't get the $300 per kW Ameren/ComEd rebate. What they do get is Illinois Shines, which is open to systems connected to co-op and municipal grids too. Our SREC prices guide has the full 2026-27 table.

If you want a fuller picture of how cost, incentives and credits add up to a break-even year, our solar payback period guide walks through it.

The lease catch

This is the one I'd want to know before I sat down with any salesperson.

On Ameren and ComEd, a solar lease works smoothly. The leasing company owns the panels and you get the credits on your bill. On a co-op or city system, that depends on wording. Peru's 2026 policy offers net metering for systems "owned by the customer." Illinois Electric's Small DG credit is for systems "owned by a member." Where the policy reads that way, a leased system may not get credit for the power it exports. A lease without bill credits doesn't make sense.

That's why on our city pages for municipal towns, like Springfield, we say lease availability gets checked address by address. In plenty of co-op and city territories, buying the system is the cleaner path. The Illinois Shines REC value comes to you as the owner, through the Approved Vendor that registers your system, and nobody's ownership has to fit the utility's definition. Our lease vs. buy comparison lays out the trade-offs. If your utility does allow third-party ownership, a lease brings $0 down and a predictable payment, with the full 25-year rate schedule set in the contract before you sign.

Access to leases and PPAs was part of the "Solar Bill of Rights" that advocates proposed, and it didn't make it into the 2026 law. Neither did clear published crediting rules, a 25-year legacy period so a utility can't cut credits on existing systems, lower meter and study fees, an Illinois Commerce Commission mediation path, or limits on interconnection fees. As of October 2026, none of those is in the statute. Until they are, the policy your utility has on file the day you apply is what you live with.

Before you sign anything in co-op or city territory

1. Get your utility's current solar policy in writing. The statute requires co-ops and city systems to post their policies on a public part of their website. If you can't find it, call and ask for it.
2. Find the crediting method and the expiration date. Retail or wholesale? Monthly, March or year-end reset?
3. Ask whether leased or third-party-owned systems qualify. Get the answer in writing.
4. Get your installer's certificate of insurance showing $1M / $2M general liability. Attach it to the application.
5. Size the system to your usage, not your roof. Unused credits that expire are money you spent for nothing.
6. Don't let anyone count the $300 per kW rebate in your quote. It's for Ameren and ComEd customers only.

Naperville customers have their own city rebate and rules. We broke those down separately in our Naperville solar guide.

Want us to check your utility's rules for you?

Send us your address and a recent bill. We'll confirm which utility serves you, pull its current solar policy, check whether a lease is available there, and show you the numbers for buying, leasing if your utility allows it, and Solar for All. You can also start with a quick look at your roof using our roof check tool.

Call or text (618) 217-2001, or reach us here.

Sources

• 220 ILCS 5/17-900, Customer self-generation of electricity, as amended by Public Act 104-0458 — Illinois General Assembly; new subsections (b)(5) and (c-5)
• Clean and Reliable Grid Affordability Act overview — Illinois Power Agency; signed January 8, 2026, effective June 1, 2026
• 220 ILCS 5/16-107.6, Distributed generation rebate — Illinois General Assembly
• Illinois Electric Cooperative Policies 285–288, Member Solar — Policy 286 revised May 11, 2026; Policy 288 revised July 13, 2026
• City of Peru Ordinance No. 7033, Net Metering and Interconnection Policies — approved April 20, 2026
• CWLP Renewable Energy and Net Metering — City Water, Light & Power, Springfield (accessed October 28, 2026)
• CWLP Solar Application Packet — June 2023 packet, fee schedule
• Illinois Shines 2026-27 Program Guidebook — Illinois Power Agency; system location and interconnection rules, Group A/B REC prices
• Solar Bill of Rights campaign — Vote Solar (advocacy organization), May 8, 2025; the provisions proposed before the law passed