Solar Panel Warranties: What Is Covered?

Warranties are the part of a solar quote people skim. They look like reassurance rather than information: a column of long numbers, all of them bigger than you expected, none of them covering quite what you assumed.

There are usually four separate warranties on a solar and battery system, they come from different places, and they protect against different things. Here is how to read them.

The product warranty on the panels

This covers the panel itself failing: a delamination, a cracked junction box, water ingress, a manufacturing fault. It is the warranty that replaces hardware.

Terms vary more than you would think. Some panels carry 10 to 12 years of product cover, while the better tier now runs to 25 or even 30 years. It is one of the few places where brand genuinely matters, because a long warranty from a manufacturer that may not exist in fifteen years is just a long number on paper. The brands we fit, Trina, JA Solar and DMEGC among them, are chosen partly on that basis.

Worth checking: whether the warranty includes labour and scaffolding to swap a failed panel, or only the panel. Panel supply is the cheap part of that job.

The performance warranty

Different thing entirely. Panels lose a small amount of output as they age, typically in the region of 0.2 to 0.5 per cent a year. The performance warranty is the manufacturer’s guarantee of how much output remains at a given point, commonly around 80 to 90 per cent of the original rating at year 25.

This is why we say panels generate for 25 years and more. They do not stop at the end of the warranty, they simply carry on slightly quieter. A 460W panel at 85 per cent is still a 391W panel, on a roof that has already paid for itself several times over if the payback came in at the usual 5 to 8 years.

Performance claims are rare and awkward to prove, because you need to show the shortfall is degradation rather than shading, soiling or a dull year. Treat this warranty as a statement of build quality more than a thing you will ever call on.

The inverter is the short one

The inverter is the component most likely to need replacing inside the system’s life, usually at 10 to 15 years, and its warranty is correspondingly shorter. Ten to twelve years is common now, and some manufacturers sell an extension.

If a battery is part of the system, it has its own warranty again, normally expressed as a number of years alongside a throughput or cycle figure and a guaranteed remaining capacity. Read both halves. Whichever limit you reach first is the one that ends the cover.

Workmanship, and who you actually claim from

None of the above covers the installation. If a roof anchor leaks or a cable is run badly, that is the installer’s workmanship warranty, which is a separate term and usually much shorter.

Behind it sits the part that matters most. As an MCS accredited, RECC registered installer, our workmanship guarantee is insurance backed, which means the cover survives the company. That is the protection worth asking about on any quote, because the warranty of a firm that has closed is worth nothing at all.

We use subcontractors for parts of some installs, which is normal in this industry. The job is ours to manage and ours to answer for, and the guarantee is issued in our name.

In practice, nearly every claim starts with your installer rather than the manufacturer, particularly as most panels are imported. A good installer handles the diagnosis, the claim and the swap. A cheap one hands you a phone number in another country.

What to keep

Your MCS certificate, issued within 10 working days of commissioning, plus the quote, the handover pack and the product datasheets. Keep them somewhere you will find them in a decade. Claims are usually won or lost on whether you still have the paperwork proving what was fitted, when, and by whom.

If you would like someone to go through the warranty terms on a quote with you, your own or somebody else’s, our survey is free and there is no obligation.