Solar warranties, decoded.

The 30-second take

• Three separate warranties: product (the hardware), performance (the output), workmanship (the installation).
• Product and performance warranties come from the manufacturer. Workmanship comes from your installer.
• The workmanship warranty is the one most likely to be tested and the one most likely to be worthless — it depends on the installer still trading.
• Australian Consumer Law guarantees sit over the top of every written warranty and cannot be contracted out of.
• A longer warranty from a company with no track record is worth less than a shorter one from a business that will still be there.

Three warranties, three different promises

People talk about “the warranty” on a solar system as though it is one thing. It is three, they are issued by different parties, they cover different failures, and they run for different lengths of time. Confusing them is how buyers end up with a system nobody will fix.

• Product warranty — covers the physical hardware against defects. Issued by the panel, inverter or battery manufacturer. This is the “25 years” you see on brochures for panels; inverters are typically much shorter.
• Performance warranty — a promise about output, not hardware. It guarantees the panel will still produce at least a stated percentage of its original rating after a given number of years. Also from the manufacturer.
• Workmanship warranty — covers the installation itself: the mounting, the cabling, the roof penetrations, the switchboard work. Issued by your installer, not the manufacturer.

The critical distinction: a manufacturer defect is the manufacturer’s problem, but almost everything that actually goes wrong on an Australian roof — leaks, loose racking, poor cable management, corrosion, sloppy switchboard work — is a workmanship problem. And workmanship is the warranty backed by the smallest, most fragile party in the transaction.

What a performance warranty is really saying

A performance warranty typically reads something like “at least 80–90% of rated output at 25 years”, with a stated maximum decline per year. It is a degradation promise written in legal language, and it is worth understanding what it does and does not commit to.

It does not promise your system will generate a particular number of kilowatt-hours. Output depends on your roof, your orientation, shade, dirt and the weather — none of which the manufacturer controls. It promises only that the panel itself will not have degraded past a stated threshold.

• It is measured under test conditions, not on your roof. Claiming against it usually means having panels tested, which is a real hurdle.
• The first-year drop is often larger and separately stated. Read the year-one allowance, not just the 25-year figure.
• A stronger degradation curve is a genuine quality signal. It is one of the few places where premium panels are measurably different on paper.

Why the workmanship warranty is the one that matters

If a panel fails, the manufacturer replaces the panel — but someone still has to get on your roof, remove it, fit the replacement and make the system safe. That labour is workmanship, and it is on your installer.

This is why a manufacturer warranty on its own does not protect you. A 25-year panel warranty with no one willing to do the labour is a piece of paper. The Clean Energy Regulator inspected 1,278 home battery installations between July 2025 and April 2026 and classified more than 60% as substandard — overwhelmingly installation faults, not hardware faults, on systems using reputable brands.

“A 25-year panel warranty is worth exactly as much as the company willing to climb up and honour it.”

The law sitting above all of it

Australian Consumer Law provides consumer guarantees that apply automatically to goods and services, separately from — and in addition to — any written warranty. Businesses cannot contract out of them, and a written warranty that claims to limit your rights does not override them.

In practice that means a system which fails well before a reasonable person would expect may give you rights even after the written warranty has expired, because the guarantee is based on what is reasonable for the goods, not on a date in a document. Where a failure is major, the remedy can extend to a replacement or refund rather than just a repair.

This is genuinely useful protection, but it is not a substitute for buying from someone competent. Enforcing consumer guarantees against a company that has been deregistered is a slow, often fruitless process — which brings us to the real risk.

What to check before you sign

• Get all three warranties in writing, with the durations stated separately. “10-year warranty” on a quote is meaningless until you know which of the three it refers to.
• Check who issues each one. Manufacturer warranties should be in the manufacturer’s name, not the retailer’s.
• Ask who performs the labour on a manufacturer warranty claim, and whether that labour is charged.
• Check the installer’s trading history, not just the warranty length. A 25-year workmanship warranty from a two-year-old business is a marketing number.
• Keep your documents. Quote, invoice, compliance certificate and warranty paperwork. Claims are much harder without them.

The uncomfortable arithmetic: warranty length is free to promise and expensive to honour, so the companies most willing to advertise long warranties are not always the ones most able to deliver them. Get matched with 2-3 vetted installers — typically 2+ years in business with a track record of decent reviews — and compare the businesses as carefully as you compare the paperwork.

Read next

• What happens if your installer goes out of business
• How to choose a good solar installer
• How to read a solar quote line by line
• Is solar worth it in Australia?

Sources

• accc.gov.au — consumer guarantees
• accc.gov.au — repair, replace, refund, cancel
• uts.edu.au — CER battery inspection findings, April 2026
• cleanenergycouncil.org.au — buying solar