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What are the steps, in order?
Illinois Shines, the state solar program, lists its own steps. We put them next to the utility's steps, so you can see the whole path in one place.
- Sign the disclosure form, then the contractThe installer must give you a state disclosure form and brochure first. It cannot start the state application until you sign the form
- Design and permitThe installer designs the system and files the city or county permit. A homeowners association may need to approve it too
- State application (Illinois Shines Part I)The installer files it and has 14 days to fix errors. The Illinois Commerce Commission approves batches about every 2 weeks
- Utility applicationThe installer files with ComEd or Ameren Illinois. A normal home system uses the fastest track, called Level 1, with a $50 fee
- InstallThe crew mounts the panels and inverter. Your disclosure form lists the planned start and finish dates
- Inspection and testYour city or county inspects. Ameren runs a test visit. ComEd asks for photos of the inverter labels, the inspection proof and the as-built drawings
- Permission to operateYour utility signs off in writing. Then you switch on, and bill credits start within 1 to 2 months. Extension says the final hookup typically takes up to 10 business days after inspection
After switch-on, your installer sends the state a second form, called Part II, to prove the system works. The state then pays the installer, not you. For a system of 25 kW or less, half of that money comes when the system is energized. Our Illinois Shines guide shows what it pays and how to make sure it lowers your price.
The seven steps overlap. A good installer files the utility application as soon as the design is done, and does not wait for the roof work.
How long does each step take?
The state sets some of these times by rule. Your utility sets others in its own guide. Some steps have no published time at all, and the table says so. We read every source on October 25, 2026.
| Step | Time allowed | Who sets it |
|---|---|---|
| Utility says your application is complete | 7 business days | Illinois Commerce Commission rule |
| You fix missing information | 10 business days, or the request is dropped | Illinois Commerce Commission rule |
| Utility checks your design | 15 business days after "complete" | Illinois Commerce Commission rule |
| You sign the utility agreement | 30 business days, then it is dropped | Illinois Commerce Commission rule |
| Ameren Illinois test visit | Within 15 business days of your "done" notice | Ameren Illinois guide, June 2023 |
| Ameren Illinois permission to operate | Usually 2 business days after the test | Ameren Illinois guide, June 2023 |
| Final hookup after inspection | Typically up to 10 business days | University of Illinois Extension |
| ComEd permission to operate | No time published | ComEd requirements, September 2026 |
| Illinois Shines Part I errors | 14 days to fix | Illinois Shines |
| State contract signed | 1 to 2 weeks after approval, then the installer has 7 business days | Illinois Shines |
| Finish the install | Up to 18 months after approval | Illinois Shines |
| Design and city permit | No time published. Ask your installer and your city | Local rules |
Add the 7 days to the 15 days and you get 22 business days, about four and a half weeks. That is the longest the state lets a utility take on a complete home application. If the application is missing something, the 10-day fix window can push it to 32. A home system gets this fast track when it sends 25 kW or less to the grid, is 50 kW or less in all, and uses an inverter with lab-certified equipment.
A late filing costs you the most. Some installers send the utility application only after the install. That puts the whole review at the end, and the panels sit idle. Ask when they file.
Plan your own dates
Type the day you plan to sign, and the times your installer quotes for design, permit and inspection. The planner adds the published utility times and shows when you could switch on.
Type the dates your installer quotes. The tool adds the review times the state and your utility publish, and shows when you could switch on.
This tool could not start. The steps and their published times are in the table above it.
This is a planning aid built from the published limits in the table above. Your installer and utility set the real dates, and weekends are the only days it skips.
What fees show up along the way?
Most of your cost is the system itself, which our cost guide covers. These are the smaller fees tied to the steps.
| Fee | Amount | Where it comes from |
|---|---|---|
| Utility application for a standard home system | $50 | ComEd and Ameren Illinois guides |
| Most you can be billed for the Level 1 hookup | $200 cap. Costs above it go into delivery rates | Illinois Commerce Commission rule |
| Optional report on your circuit, before you apply | $300 at ComEd | ComEd requirements, September 2026 |
| Illinois Shines application fee | Must be shown on your Disclosure Form | Illinois Shines |
| City or county permit | Varies. Chicago lists its own | Chicago solar permits |
If a quote lists $200 as your utility application fee, ask why. The $200 is a cost cap, not the application fee.
What do you do, and what does your installer do?
The installer does the filing. You do a few things only you can do.
- You read and sign the state disclosure form before the contract. It lists the full price, the deposit, the warranties and the estimated start and finish dates.
- You pick the installer. Check the Illinois Commerce Commission list of certified installers and the Illinois Shines list of approved vendors.
- You let the inspector in. Illinois Shines inspects a random share of projects at no cost to you. You may decline.
- You ask for written proof that net metering is set up, so credits start on your bill.
- You do not file the Illinois Shines application. Only an approved vendor can.
- You do not switch the system on before the utility says yes.
- You do not climb on the roof for any inspection. The program tells customers not to.
Can you install solar panels yourself in Illinois?
Sometimes, but it is hard. Illinois law has a "self-installer": a person who buys or leases a system for their own use and puts it in on their own property with no help from anyone else. Your utility needs your written statement that you are one before it will give you net metering.
Everyone else who connects the system must be certified by the Illinois Commerce Commission. A friend or an uncertified electrician does not count, and a self-installer cannot have help.
Three things still apply. Your city or county still needs a permit and an inspection. The utility still reviews the design and sets the switch-on. And the Illinois Shines application must come from an approved vendor, so you may lose the state's solar credit money. Ameren Illinois's own solar page calls solar "not a DIY project." We could not confirm whether a vendor will file for a system you built, so call Illinois Shines at (877) 783-1820 before you buy parts.
What slows an install down?
Most delays are paperwork, not roof work.
- A late or incomplete utility application. A missing page can add 10 business days before the 15-day check even starts.
- Waiting on the state contract. Some installers wait for it before they start. Ask if yours does.
- A roof that needs repair first. Panels outlast a worn roof, and taking them off to re-roof is costly. The Illinois Solar Energy and Storage Association suggests a roof with at least 15 years left.
- An HOA review. It cannot ban panels, but it can slow the plan. See what an Illinois HOA can require.
- Inspection scheduling. Cities set their own pace. Chicago and Aurora publish theirs: Chicago, Aurora.
Is your home ready for these seven steps?
Solar is a poor fit in some homes, and it is better to know before you sign. Be careful if:
- Your roof is within about 10 years of a replacement. Re-roof first, or the panels will have to come off and go back on. See Illinois roof requirements.
- Shade covers the roof in the middle of the day. Measured shade decides this, not guesses. See solar on a shaded roof.
- You rent, or live in a building you do not own. You cannot put panels on it. Community solar is the option to read.
- You may move within a few years. Read selling a house with solar first.
If none of those apply, the free solar check looks at your roof, shade and usage and tells you if solar fits. When it does not fit, it says so. For the cost side, see what solar costs in Illinois.
Who should install it?
Check any company the same way. Do three lookups before you sign: the Illinois Commerce Commission list of certified installers, the Illinois Shines approved vendor list, and the program's complaints and violations reports. We explain each lookup in how to verify a vendor, and what to ask in is my quote a good deal. We do not rank installers on this page.
Questions, answered
How long does it take to install solar panels in Illinois?
The roof work is short, and your disclosure form lists the planned dates. Start to finish takes longer, because the utility review alone can take 22 business days under state rules, plus the permit, the inspection and the final hookup. The planner above adds up your own dates.
Do you need a permit to install solar panels in Illinois?
Almost always, from your city or county. Rules and fees vary. We cover two big ones in our guides to Chicago solar permits and Aurora solar permits.
Is it worth installing solar panels in Illinois?
For many owner-occupied ComEd and Ameren homes, yes, but it depends on your roof, your use and the deal. We lay out the math in is solar worth it in Illinois.
What is the typical cost of installing solar panels in Illinois?
Our cost guide puts a typical 9.4 kW home system at about $34,000 to $35,000 before incentives in 2026. See the current figures in solar panel cost in Illinois.
Is the state of Illinois paying for solar panels?
Not directly. Illinois Shines pays your installer for the solar credits your system makes, and the installer may pass some of that on as a lower price. ComEd and Ameren also pay a rebate, and income-eligible homes can use Illinois Solar for All. See ComEd's solar rebate.
What is the 33% rule in solar panels?
It usually means a fire-code limit on how much of the roof panels may cover before wider walkways are needed. It is set by local code, and we found no Illinois statewide roof-coverage rule. Ask your city's permit office.
Why are people getting rid of their solar panels?
The common reason is a roof replacement, which means paying to take the panels off and put them back. Moves and leased systems are others. That is why roof age matters before you sign.
Who files the ComEd or Ameren application?
Your installer, in most cases. ComEd urges applicants to use its online portal, and Ameren Illinois uses PowerClerk. Both list a $50 fee for a standard home system.
When do bill credits start after install?
Illinois Shines says credits generally show up within 1 to 2 months of net metering being set up.
What do you want to do next?
Check that your roof can take the seven steps.
See in about a minute if solar fits your roof. It's free, and if it's not a fit, it says so.
Free eligibility check · ComEd & Ameren · No obligationThe Day Company is an independent solar, battery and electricity information resource. Information you submit may be used by our review team and authorized partners to contact you about your request. Checking eligibility creates no obligation.
Sources and updates
Sources (12)
- Illinois Shines, Project Status: program steps: The seven program steps, 14-day error fix, ICC review rhythm, 18 months to install, 50% payment, credits in 1 to 2 months. Read October 25, 2026.
- Illinois Shines, Consumer FAQs (updated January 2026): Approvals list, only an Approved Vendor may file, inspections, net metering enrollment. Read October 25, 2026.
- Illinois Shines, Explore Distributed Generation: What a Disclosure Form lists, including start and finish dates. Read October 25, 2026.
- Illinois Commerce Commission, 83 Ill. Adm. Code 466.80, Determining the Review Level: Level 1 limits: 25 kW export, 50 kW nameplate, inverter-based, lab-certified. Read October 25, 2026.
- Illinois Commerce Commission, 83 Ill. Adm. Code 466.90, Level 1 Expedited Review: The 7, 10, 15 and 30 business-day clocks and the $200 cost cap. Read October 25, 2026.
- Illinois Commerce Commission, Distributed Generation Installer: Installers must be certified, except self-installers (Part 468). Read October 25, 2026.
- Illinois General Assembly, 220 ILCS 5/16-128A: The self-installer definition and the utility's certification rule. Read October 25, 2026.
- ComEd, DER Interconnection Requirements for Interconnection Customers, Rev. 3 (September 10, 2026): $50 Level 1 fee, the certificate of completion, and the warning about switching on early. Read October 25, 2026.
- Ameren Illinois, Distributed Energy Resources Interconnection Policy Public Facing Guide (June 21, 2023): $50 Level 1 fee, the 15-business-day test and the 2-day permission to operate. Read October 25, 2026.
- Ameren Illinois, Customer-Owned Solar: Calls solar "not a DIY project" and says a certified installer submits the paperwork. Read October 25, 2026.
- University of Illinois Extension, Homeowner's Guide to Solar Energy: The order of permit, inspection and utility hookup, and "up to 10 business days after inspection approval." Read October 25, 2026.
- Illinois Solar Energy and Storage Association, The Solar Installation Process: The suggestion of a roof with 15 or more years left. Read October 25, 2026.
Changelog · last updated October 25, 2026 · 1 update
- October 25, 2026: Guide published.
How to cite this page: The Day Company, "How does solar panel installation work in Illinois, and how long does it take?", updated October 25, 2026, https://theday.company/answers/solar-panel-installation-illinois.
We are not part of Illinois Shines, ComEd, Ameren Illinois or the Illinois Commerce Commission. Times and fees are the published limits on the read date. Your installer, city and utility set the real dates. This page is information, not legal advice.