Solar Answers → Incentives & Programs

Do solar panels raise property taxes in Illinois?

Independent public sources we cite and link — The Day Company is not affiliated with or endorsed by any of them.

Published July 21, 2026 · Facts verified July 2026 · By The Day Company Editorial Team

How does Illinois' solar property tax break actually work?

Under 35 ILCS 200/10-10, an installed solar energy system entitles the property owner to an alternate valuation: the assessor calculates your property's value both as if equipped with a conventional system and as equipped with solar, then applies whichever is lower. It's often called the Illinois solar property tax exemption, though it's technically a special assessment — and it applies statewide, ComEd and Ameren territory alike.

This is separate from Illinois Shines, the ComEd/Ameren solar and battery rebates, and net metering — those are utility and state incentive programs; this is a property tax provision. See our Illinois Solar Incentives guide for the full stack.

What is Form PTAX-330, and how do you file it?

PTAX-330, Application for Solar Energy Assessment, is the one-time form you file with your county's chief county assessment officer — not the state, and not automatically. Attach your installation cost and receipts. This is general information, not tax or legal advice; confirm specifics with your county assessment office before filing.

Filing at a glance:

Built from 35 ILCS 200/10-10 and consistent county chief county assessment officer filing pages. Illinois' Department of Revenue does not publish a fee or a fixed filing deadline for this form — we haven't invented one.

Which systems and owners qualify?

The break covers residential solar energy systems on your property, including those that generate electricity primarily for your own use — not just solar heating or cooling. Illinois law also explicitly covers systems under a lease or power purchase agreement, so long as the system sits behind your meter and is sized to roughly match your own household's usage.

The right to claim the alternate valuation belongs to the property owner, not necessarily whoever owns the solar equipment — so a leased or PPA system doesn't block you from filing. If you expand your system later, confirm with your assessor's office whether an updated filing is needed; the statute doesn't spell that scenario out. Considering a lease versus buying? Our lease vs. buy guide covers how ownership affects your other incentives too.

Does battery storage qualify?

Illinois law doesn't clearly answer this. The statute defines a "solar storage mechanism" entirely in terms of thermal storage — piping, containers, heat exchangers, and the gases, solids, or liquids that carry heat — with no mention of batteries or electrochemical storage anywhere in the definition. Whether a home battery counts is genuinely unresolved.

We'd rather tell you that plainly than guess. Confirm directly with your county assessment office before assuming a battery is included in your PTAX-330 filing — and see our ComEd Battery Storage Rebate guide for the separate utility rebate a battery can earn, which is unrelated to this property tax question.

Does solar raise your home's value — and your taxes with it?

Research from Lawrence Berkeley National Laboratory points both directions: owned solar systems have shown a sale premium that varies by market, while homes with leased or third-party-owned systems have sold at roughly the same price as comparable homes without solar. Either way, once you've filed Form PTAX-330, your assessment is capped at the conventional-system value regardless of what solar adds to your market price.

Selling later? Our guide to selling a house with solar in Illinois covers what happens to this valuation, and to owned versus leased systems, at closing.

Is there an Illinois sales tax exemption for solar too?

No. Despite what some guides claim, Illinois has no sales-tax exemption for residential solar equipment or installation — that claim isn't in Illinois law. The property tax break covered on this page is real and specific; a separate sales-tax break for solar simply doesn't exist here.

If you came here worried solar would raise your tax bill, it won't — provided you file. If you're ready to see what solar could mean for your own home, a free eligibility check takes about a minute.

Illinois Solar Property Tax FAQ

Do solar panels increase property taxes in Illinois?

No, as long as you file Form PTAX-330. Illinois law lets your assessor value your property both with and without the solar system and uses whichever is lower — so a solar installation doesn't raise your assessment, provided you've made the filing.

Is this really a "solar property tax exemption"?

It's commonly called that, but it's technically a special assessment or alternate valuation under 35 ILCS 200/10-10, not an exemption. The distinction matters less than the filing requirement does — either way, you have to file to get it.

What is Form PTAX-330?

PTAX-330, Application for Solar Energy Assessment, is the form you file with your county's chief county assessment officer to claim the alternate valuation. Attach your installation cost and receipts when you file.

Do I have to file PTAX-330 every year?

No — it's a one-time filing. The alternate valuation stays in place as long as the solar energy system remains in use. If you ever stop using it, Illinois law requires written notice to your assessment officer within 30 days, by certified mail.

Does a leased or PPA solar system still qualify?

Yes, generally. Illinois law specifically covers photovoltaic systems under a lease or power purchase agreement, as long as the system is behind your meter and sized to roughly match your own usage. The right to claim the valuation belongs to the property owner, not whoever owns the panels.

Does adding a battery change my property tax assessment?

Illinois law doesn't clearly say. Its definition of a "solar storage mechanism" is written in thermal-storage terms and doesn't mention batteries. Confirm directly with your county assessment office before assuming a battery is included in your filing.

Is this the same as the federal solar tax credit?

No — completely separate programs. This is a state property tax provision with no expiration date. The federal residential credit (Section 25D) expired December 31, 2025 and doesn't apply to 2026 purchases.

Does the property tax break ever expire?

Not on its own — the alternate valuation applies for as long as the solar energy system is installed and in use. It ends only if you remove the system or stop using it, which triggers a notice requirement to your assessment officer.

Does it matter if my system is roof-mounted or ground-mounted?

Not under the residential provision — Illinois' definition doesn't require roof-mounting. What matters is that the system primarily serves your own property's electricity use rather than generating power for sale, which is what separates it from Illinois' commercial solar valuation rules.

What happens if I stop using my solar energy system?

Illinois law requires you to notify your chief county assessment officer in writing, by certified mail, within 30 days of discontinuing use. After that, your property would presumably return to a standard valuation.

Related answers

Sources

• Illinois Compiled Statutes, 35 ILCS 200/10-5 — Solar Energy Systems; Definitions (ilga.gov)
• Illinois Compiled Statutes, 35 ILCS 200/10-10 — Valuation of Solar Energy Systems (ilga.gov)
• Illinois Department of Revenue — Solar Energy Systems (tax.illinois.gov)
• Illinois Department of Revenue — Commercial Solar Energy Systems Valuation (tax.illinois.gov)