guide6 min read

Do Solar Panels Increase Your Property Taxes in Illinois? (2026)

Ryan Cook•July 9, 2026•Updated Sep 15, 2026

A guy in Naperville asked me a good question last spring, right before he signed. Not about savings, not about panels — about his tax bill. "If solar makes my house worth more," he said, "doesn't the county just come tax me on it?" Fair worry. His neighbor had put on an addition and watched his assessment climb.

The answer in Illinois is no. And it's worth understanding why, because it's one of the few homeowner protections that survived everything that changed in 2026.

A two-story suburban Illinois home with rooftop solar panels in warm late-afternoon light

The short version

Illinois has a law on the books called the Special Assessment for Solar Energy Systems. It lives at 35 ILCS 200/10-5, and it's been there for years. What it does is simple: it keeps the value your solar system adds to your home from raising your property taxes.

That's the whole promise. Add panels, your home is probably worth more, and normally a higher value means a bigger tax bill. This law breaks that chain for solar specifically.

The catch — and there's always one — is that it isn't automatic. You have to claim it. More on that below.

How the special assessment actually works

Here's the mechanism, because it's cleverer than a flat exemption.

When you file the claim, your county assessment officer is required to calculate two separate values for your property:

What your home is worth with a conventional heating and cooling setup.
What your home is worth with the solar energy system in place.

Then they assess you at the lesser of the two. Since solar almost always adds value compared to a plain conventional system, the solar-added value effectively drops out of the equation. You're taxed as if the panels weren't there.

It covers residential, commercial, and industrial property, and it applies to both active systems — the photovoltaic panels most people picture — and passive solar design. What it won't cover is a part that would work just fine in a non-solar system, or components that are really doing a structural, insulating, or decorative job. The exemption is for the solar, not for dressing up the rest of the house as solar.

The step people skip

The valuation doesn't happen on its own. You file a form.

It's called the PTAX-330 — Application for Solar Assessment, and it goes to your local county assessor's office. It's one page, there's no fee, and you can pull it off your county assessor's website or the Illinois Department of Revenue. Once it's filed and on record, the alternate valuation stays in place as long as the system is in use. You don't refile every year.

My honest advice: file it the same season your system goes in, before your township runs its assessment cycle. I've seen homeowners assume it was handled by someone else and never actually submit it. Ten minutes of paperwork protects the benefit for the life of the system. I'm not a tax advisor, and every county runs its office a little differently, so if anything about your situation is unusual, call your assessor and ask — they answer this question all the time.

If you're leasing, this is a non-issue

Everything above is about owned systems — cash or financed. If you go the lease or power-purchase route, you don't own the equipment on your roof. The provider does.

Property tax is assessed on what you own. So leased panels generally don't add a dime to your assessed value, and there's no PTAX-330 for you to file. You get the lower monthly electricity cost without the equipment ever becoming a taxable asset in your name. It's a quiet advantage of leasing that never shows up in the sales pitch, and for a lot of Illinois homeowners it's one less thing to think about.

If a lease later converts to ownership, that's the moment to circle back and file for the special assessment.

One point of confusion worth clearing up

If you go searching, you'll hit the Illinois Department of Revenue's page on Public Act 100-0781 and wonder if it changes any of this. It doesn't — not for a homeowner. That act deals with how property taxes get calculated on the land hosting large ground-mounted commercial solar farms, the utility-scale projects out in the fields. Different animal entirely. The special assessment for the panels on your roof is the 35 ILCS 200/10-5 provision, and that's the one that matters for your house.

Why this lands differently in 2026

A tax detail like this used to be a footnote. It carries more weight now.

The federal residential tax credit for customer-owned systems ended at the close of 2025 — I wrote about what that actually changed for Illinois homeowners. With that gone, the remaining owner-side incentives matter more, and a property-tax protection that never expires is a real one.

Meanwhile the bills keep climbing. Summer supply rates reset June 1 to 11.326¢/kWh at Ameren Illinois and 10.399¢/kWh at ComEd, which land around 20¢ and 18¢ all-in once delivery and fees stack on. You can see where your own rate sits on our Ameren and ComEd pages. The case for solar is getting stronger on the electricity side, and the tax side isn't working against you the way a nervous homeowner might assume.

The bottom line

Adding solar in Illinois can raise your home's value without raising your property taxes — as long as you own the system and file the PTAX-330 for the special assessment. Lease the system instead, and the question disappears, because you don't own the equipment. Either way, the fear that the county will punish you for going solar just doesn't hold up here.

If you're weighing solar and want a straight answer on how it touches your taxes, your home's value, and your monthly bill — or whether buying or leasing makes more sense for your house — that's what I'm here for. I'm a local installer who reads this stuff for a living. Run your numbers on the savings calculator, or just call or text (618) 217-2001 and I'll walk you through it. You can also reach us through our contact page.

Frequently Asked Questions

In Illinois, no — not if you file for the state's special solar assessment. Solar panels usually raise a home's market value, and normally a higher value means a higher property tax bill. Illinois carves out an exception. State law lets your county assessor value your home two ways: once as if it had a standard heating and cooling system, and once with the solar system included. Your property is then assessed at the lower of those two figures. In plain terms, the added value your panels bring doesn't get taxed. You do have to claim it, though — it isn't automatic. You file a one-page form called the PTAX-330 with your county assessor's office. Miss that step and an assessor could, in theory, fold the panels into your assessment. File it, and the solar value stays off your tax bill for as long as the system is in place.

It's officially called the Special Assessment for Solar Energy Systems, written into Illinois law at 35 ILCS 200/10-5. Rather than a flat dollar discount, it changes how your home gets valued for tax purposes. When you file a claim, the county assessment officer figures two values: your improvements as if equipped with a conventional heating or cooling system, and your improvements as actually equipped with solar. The assessment uses the lesser of the two. Because a solar system almost always adds value versus a plain conventional setup, the practical result is that the solar portion isn't taxed. It applies to residential, commercial, and industrial property, and covers both active photovoltaic panels and passive solar designs. It does not cover parts that would work just as well in a non-solar system, or components that are really structural, insulating, or decorative. The exemption lasts as long as the system stays in service.

You file Illinois form PTAX-330, the Application for Solar Assessment, with your local county assessor's office. It's a short form, and it's available on your county assessor's website or through the Illinois Department of Revenue. There's no fee to file it. The claim has to be made for the property where the system is installed, and once it's on record the alternate valuation stays in place while the system remains in use — you don't refile every year. My advice is to file it the same season your system is installed and energized, so the paperwork is in before your township's assessment cycle runs. If you bought the system with cash or a loan, this is a step worth putting on your calendar, because the exemption isn't applied automatically. If you're on a lease, the equipment isn't yours to begin with, so the filing usually falls to the system owner, not you. When in doubt, ask your county assessor directly.

Generally, no. With a solar lease or a power purchase agreement, you don't own the equipment on your roof — the provider does. Property tax is assessed on what you own, so leased panels typically don't add anything to your home's assessed value or your tax bill. That's one of the quieter advantages of the lease path that nobody puts on a flyer. You get the lower monthly electricity cost without taking on the equipment as a taxable asset, and without any form to file. If you later buy the system out or the lease converts to ownership, that's the point where you'd want to look at the special solar assessment and file the PTAX-330. For most Illinois homeowners weighing lease versus buying, property tax isn't the deciding factor either way — the state protects owned systems and leased systems sidestep the question entirely — but it's one more thing that quietly favors going solar rather than avoiding it.

Most evidence says yes — solar tends to raise a home's value, and buyers in Illinois increasingly treat panels as a feature rather than a question mark, especially with utility rates where they are. National studies have estimated the bump at roughly 4% for owned systems, though the real number depends on your market, your system size, and whether the panels are owned or leased. Here's the part that matters for taxes: in Illinois, that added value doesn't have to translate into a higher property tax bill, because the state's special solar assessment keeps it off your assessment when you file for it. Leased systems are a different story at resale — the buyer typically assumes the lease rather than paying for equipment — which is why I walk sellers through that separately. If you're thinking about resale, the value question and the lease-transfer question are worth sorting out before you list, not after.