Guide
Solar panel warranty: what each one covers and what to ask
A solar panel warranty can be several. What to ask about panels, inverter, installation and roof, what the FTC says to check, and how fast panels wear.
Updated October 26, 20264 min readReviewed by SolarRealCost Editorial Team, editorial review: primary sources checked and independently fact-checked
A solar panel warranty is only as good as what it says in writing, and a home system can come with more than one. The FTC tells solar shoppers to get in writing which warranties apply to the equipment, like the panels and inverters, and to the installation workmanship. The Federal Trade Commission's rule of thumb for any warranty applies: if something isn't listed, assume it isn't covered.
What a solar panel warranty is, and what the FTC says to check
The Federal Trade Commission's consumer page on warranties defines a warranty as "a promise to stand behind the product." Warranties "might cover a lot or a little, but the details should be in writing." It also notes that "laws in every state create implied warranties," unspoken promises that cover products even without a written warranty.
Its questions work well for each solar warranty:
- Do you contact the manufacturer for help, or go back to the original seller?
- What's covered? "A warranty won't necessarily cover all situations or repairs."
- Are specific parts or repairs not listed as covered? "If they aren't listed, assume they aren't covered."
- How long does it last?
It also says to save a copy of the warranty along with your receipt, and to look up the company's name with the words "complaint" or "review" before you buy.
The warranties on a home solar system
The FTC's solar guidance says a bid should state "what warranties apply to the equipment (like the panels and inverters ...) and the installation workmanship." Ask for each of these in writing, with its term:
| Part | What to ask |
|---|---|
| Panels | Who issues this warranty: the panel maker or the installer? Does it cover defects only, or also promise a minimum output after a set number of years? |
| Inverter (or microinverters) | Who issues this warranty? How long is the term, and does it include labor to replace it? |
| Installation work | Who gives the workmanship warranty, what does it cover, and for how long? |
| Roof penetrations | Who is responsible if the roof leaks where the mounts go through, and for how long? |
Our checklist of what a solar quote must show includes the roof penetration warranty and the workmanship warranty, each with its term, among the lines to get in writing.
How fast panels wear, and what that means for the warranty
Panels lose a little output every year. A National Renewable Energy Laboratory review of degradation rates assembled nearly 2,000 rates measured on modules and systems in field testing over 40 years and found "a median value of 0.5%/year." The same review notes that as panel durability increased over the decades, "module warranties increased accordingly."
So when a panel warranty promises a minimum output after a number of years, compare it with that kind of wear. Our guide to how long solar panels last covers the rest of the system's lifespan.
Don't skip the inverter warranty
The inverter is the part you should expect to replace. The Department of Energy's design basics say "it is expected that inverters will need to be replaced at least once in the 25-year lifetime of a PV array." A long panel warranty tells you nothing about the inverter, so ask for its term separately, and whether labor is included.
When the installer is no longer around
Before you sign, ask who would honor each warranty if the installer closed: which ones the equipment makers back directly, and what would happen to the workmanship warranty. Our guide to what happens when your solar installer goes out of business covers who to contact then. It's also a reason to weigh who stands behind the installation when you compare quotes, alongside the price.
The Department of Energy's homeowner guide collects resources worth reading alongside any proposal.
Bottom line
A solar panel warranty can be a set of warranties; ask what covers the panels, the inverter, the installation work and the roof penetrations, and who stands behind each. Get each in writing, check what's excluded and for how long, and remember that panels wear slowly while inverters are expected to need replacing at least once. Then compare the whole offer, coverage included, against what solar costs to install.
Common questions
What does a solar panel warranty cover?
Only what the written warranty says. The FTC's advice for any warranty is to check what's covered and for how long, and to assume anything not listed isn't covered. For solar, the FTC says to get in writing which warranties apply to the equipment, like panels and inverters, and to the installation workmanship.
How much do solar panels degrade?
A national lab review of nearly 2,000 degradation rates from field testing found a median of 0.5% a year. Ask what minimum output, if any, the panel warranty promises and for how long.
Is the inverter covered by the panel warranty?
Ask for the inverter's warranty terms separately. The Department of Energy expects inverters to need replacing at least once in the 25-year lifetime of a solar array, so the inverter warranty matters.
What happens to the warranty if my installer goes out of business?
Ask before you sign: which warranties are backed directly by the equipment makers, and what happens to the installer's workmanship warranty if the company closes. Our guide to an installer going out of business covers who to contact.
Sources
- Federal Trade Commission: Warranties
- Federal Trade Commission: Solar Power for Your Home
- National Renewable Energy Laboratory: Photovoltaic Degradation Rates, An Analytical Review (2012)
- U.S. Department of Energy: Solar photovoltaic system design basics
- U.S. Department of Energy: Homeowner's guide to going solar
By SolarRealCost Editorial Team. First published October 26, 2026. Advertiser disclosure
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