My name is Jason Pope from Selec Group, and we are solar installers. We need to talk warranties, because they came up with a customer this week and they are an interesting subject. People see “25 year warranty” on one panel and “15 year warranty” on another and assume the shorter one is worse. It is not that simple. In this post I will explain the difference between the two types of warranty, what the numbers really mean, what actually happens if a panel fails, and why I read a warranty mainly as a sign of quality.
Two warranties, not one
A solar panel usually comes with two separate warranties, and they cover different things:
- Product warranty: this covers the panel against failure. If the panel itself fails or develops a fault, this is the cover that applies.
- Performance warranty: this covers degradation. Every panel slowly produces a little less power as the years pass. The performance warranty guarantees the panel still produces at least a set percentage of its rated output by a given year.
So one number is about the panel breaking, and the other is about the panel quietly getting weaker. Both matter, and they are not the same thing.
What 25 and 30 years really mean
The panels on this job are JA Solar, glass on glass, all black, 465 watts. They carry a 25 year warranty against failure and a 30 year warranty on performance degradation.
In plain terms:
- For 25 years, the manufacturer stands behind the panel against failure.
- For 30 years, the manufacturer guarantees the panel will still be producing a certain percentage of its original output.
That 30 year performance figure is the promise that the panel does not fade away. It will still be doing real work three decades from now.
Glass on glass, briefly
It is worth a quick word on what these panels are, because it ties into the warranty.
Glass on glass means there is glass on the front and glass on the back, rather than a glass front and a plastic backing sheet. Two sheets of glass make the panel tougher and more stable over its life, which is part of why a manufacturer is willing to put a long warranty behind it. From the ground the back glass can look faintly silver, but the panel reads as all black.
Is a 15 year warranty long enough?
Here is what prompted the question this week. There was another panel, from the same manufacturer, but for whatever reason its warranty had not caught up yet, and the cover offered was 15 years. The customer asked, is 15 years long enough, and what does it actually mean?
My honest view is that a 15 year warranty is not a red flag. For a long established company to offer 15 years, they are saying the panel is good and not going to fail. It is a sign of confidence, not a warning.
I read a warranty mainly as an indication of quality. It tells you how confident the maker is in their own production. The solar panels being made today are good and consistently produced, and a reputable manufacturer offering 15 years is telling you exactly that.
Why a longer warranty is not always what it seems
Here is the part people do not expect. If a company offers 25 years, to a certain extent they might as well offer 40. Let me explain what really happens if a panel fails.
If a panel fails while it is still in warranty, you go back to the manufacturer. At that point one of two things happens:
- They say yes, here is a replacement. It is a modern equivalent, probably a different size, but here it is.
- They say, back in the day these panels cost a certain amount, so with inflation we will give you this much, and they pay out a small sum of money.
Either way, the warranty rarely hands you a like for like swap years down the line, because the original panel no longer exists. So the headline number matters less than people think.
What actually happens at a claim
Picture it 15 years from now. One panel out of your set has failed. To reach it you need scaffolding up again. So what do you do?
You have two realistic choices:
- Leave the single dead panel and accept the small loss of output.
- Replace it, which means scaffold and labour for one panel.
But here is the thing. By then, the rest of your panels will be old too, and far better panels will exist. Remember the trajectory: 15 years ago panels were 275 watts, these are 465 watts, and future ones will be higher density still.
So in practice, when the scaffold is up anyway, many people replace the whole array rather than chase a single panel. You were likely going to upgrade around then regardless. That is why the exact warranty length on one panel is less important than it first appears.
Warranty as a proxy for quality
So how should you treat a warranty when comparing panels? Use it as a measure of the maker’s confidence in their own product.
- A long established firm offering a solid warranty is telling you the panel is well built.
- A slightly shorter warranty from a reputable maker is not a deal breaker.
- The bigger reassurance is a quality panel, consistently produced, fitted properly by an MCS certified installer.
We are MCS certified, which means the install is done to standard and registered, and that protects the cover that comes with your panels.
The bottom line
A solar warranty is really two things: a product warranty against failure and a performance warranty on degradation. Long numbers like 25 and 30 years are reassuring, but what a claim actually pays out is more modest than people expect, and you may well replace the whole array later anyway. Read the warranty mainly as a sign of the manufacturer’s confidence in their quality.
We fit quality solar across Cambridgeshire, Bedfordshire and Northamptonshire, in places like Grafham, Spaldwick, Huntingdon and St Ives. If you want straight answers on panels and warranties before you buy, call the office on 01480 400607 or request a survey through our website.
Jason Pope
Owner, Selec Group