Do solar panels need maintenance in Illinois, and who pays when one breaks?

Not much. Home solar has no moving parts. The federal lab's guide for keeping systems running says most systems rely on rain to stay clean and use no cleaning plan. The same guide says light rain can smear dust, while heavy rain washes it away.

Here is the whole routine for a roof system in Illinois.

A panel maker's manual backs the storm check. Qcells says to inspect "especially after extraordinary events" like storms, hail or heavy snow.

This is the best free upkeep step. Pick your nearest city, your system size, a month, and what your app says you made. The helper compares it with the federal PVWatts model for that month.

This compares your month with a model of a typical year on a south roof with no shade. Real roofs and real weather differ, so it flags a problem, not a cause. It does not diagnose anything or replace your installer.

How to read a low month

• One low month can be weather. A cloudy month is real.
• Two low months in a row is a pattern. That is our rule of thumb, not a standard, and it is why we ask you to wait one month.
• Your own last year beats any model. If you have the same month from last year, compare with that.
• Make sure you used the right number. Use what the panels made, not what you sent to the grid.

Dirt costs less than most sales pages say. The federal lab's guide quotes a study of a dusty Arizona site: soiling cost 1.91% of yearly output with no cleaning. Three cleanings a year cut that to 1.20%.

Do the math for a typical Illinois roof. Our winter guide models a 10 kW Chicago system at about 11,400 kWh a year after snow. Three cleanings recover less than one point of that, about a hundred kilowatt-hours. At ComEd's recent prices, that is under $10 a year. The same study put one cleaning of a home system at about $1 per square meter. By our math that is near $46 for a 9.3 kW roof (we assumed 20% efficient panels), at 2014 prices.

So skip routine washing. Clean when something is plainly on the glass, such as bird droppings, heavy pollen or construction dust. The federal lab warns that uneven dirt can cause hot spots.

If you do clean

1. 1
   Do it from the ground

   with a soft squeegee and plain water. The lab's guide says no high pressure, brushes, solvents or harsh soaps.

2. 2
   Skip cold mornings.

   Qcells says not to wash modules with water if there is a risk of frost.

3. 3
   Know the warranty.

   Qcells says damage from cleaning tools or agents is not covered by its warranty.

Snow is a separate question. See our winter and snow guide, and our hail guide for storm damage.

The inverter turns the panels' power into house power. The federal lab's guide says inverter failure is one of the most frequent causes of lost output. It also lists blown fuses and bad connectors among common faults.

The federal lab's sample plan also says the owner keeps shrubs and trees trimmed so the shade study still holds. A tree you let grow can cost more than a dirty panel.

Work down this list. Stop when it is fixed.

1. 1
   Check the simple things.

   Is the grid on? Is the breaker on? Is the app online? An offline app does not always mean the panels stopped.

2. 2
   Call the company that installed it.

   Send photos, the app screen and the dates. Ask for the date of the visit in writing.

3. 3
   Ask who owns the warranty.

   The panel maker, the inverter maker and the installer each cover different things. Your installer can usually start the claim.

4. 4
   If the installer is gone,

   read our guide to a solar company that went bankrupt. Then call the inverter maker. Its warranty follows the equipment's owner; Enphase's names the "Covered Owner."

5. 5
   If you used Illinois Shines,

   your vendor has a stake. The 2026-27 Guidebook says that if a verified system is offline more than 6 months, the Approved Vendor must tell the Program Administrator within 3 business days. Vendors that cannot deliver the promised RECs may have to return money. That gives the vendor a reason to fix it. It does not promise you a free repair.

6. 6
   If the credit on your bill looks wrong,

   call ComEd or Ameren. A solar fix and a billing fix are different calls. See how ComEd net metering works.

7. 7
   If nobody answers,

   file a complaint with the Illinois Commerce Commission at (800) 524-0795. It certifies solar installers under 83 Ill. Adm. Code Part 468 and can investigate on a complaint.

To check that a company is on the Illinois Shines vendor list, use our vendor check guide.

We found no Illinois installer or regulator that posts a repair price list, so use the lab's numbers and the warranty text.

Three gaps catch owners.

• Labor. Enphase's U.S. warranty does not include the cost of labor to remove a part or put in its replacement. Ask your installer who pays the labor, and for how many years.
• Connection. Enphase asks that its products stay connected to the internet so faults can be seen from afar. Keep your Wi-Fi on.
• Cleaning damage. Qcells does not cover damage from cleaning tools or agents.

SolarEdge says its inverter warranty can be extended to 20 or 25 years, depending on model, for a one-time fee. The extension must be bought within a set time after the inverter ships, so check the date on yours and ask SolarEdge for the deadline. Warranty lengths and what fails first are in our lifespan guide. If you lease or buy through a power purchase agreement, the owner may repair it for you. Your contract controls; see lease versus buy.

A new inverter is the one large repair most owners meet. Plan for the swap, and for paperwork. Illinois rules for hooking up solar say you must send the utility, in writing, any change to what is on file. The utility then has 10 business days to say whether it is a "material modification" (83 Ill. Adm. Code 466.125). A like-for-like swap is often simple. A bigger or different inverter may need a new application. Ask your installer to file the change and to give you the utility's reply.

A new roof means taking the panels off and putting them back. Ask for the price per panel in writing before you sign a roofing contract. Chicago also asks for a permit to reinstall; see our Chicago permit guide. Roof age rules are in our roof guide.

Upkeep is a small line next to the bill. About $270 a year as a model, plus one inverter swap in the system's life, is a real cost. Count it. Do not let it decide for you.

Solar is a poor fit in some homes, and we say so. Heavy shade, a roof that needs replacing in the next few years, or a rental are reasons to wait or look at community solar. If your roof is sound and mostly sunny, the free check below shows what it would make. Payback is on our is solar worth it page.

Beware of unsolicited "free inspection" calls and door knocks. A real service company will give you its name, a written price, and a place to check it. Look it up first with our vendor check guide.