When most people buy their solar panels, they ask about the warranty, in case something goes wrong. Usually they look at the product warranty, which is often 10-12 years. Then there’s the performance warranty, which is usually between 25-30 years, almost three times as long.

Many people imagine that the performance warranty isn’t really binding, however. If their panels’ output drops within the 25-30 years, there’s no point doing anything about it because the company won’t have to repair or replace the panels.

The truth is, though, that the companies do have to replace or repair solar panels that drop in efficiency. There’s no difference in Australian consumer law between product and performance warranty. Legally, a solar company has to replace a solar array anything up to 18 years after its product warranty has expired!

Product warranty

This means that manufacturers promise to replace panels if there’s any defects for 10 years (12-year warranties are becoming more common) after they’re installed. These warranties are straightforward – if a panel fails within 10 (or 12) years of installation, you can get it sorted free-of-charge.

Performance warranty

The performance warranty, AKA power output warranty, promises that the panel will produce more than aset level of energy for 25-30 years. If it falls below this level (usually 80% of rated performance) within this time, the user is entitled to restitution.

So why does there seem to be a difference?

Many panel manufacturers don’t want to be liable for restitution for 15-20 years after the product warranty has expired. However, many of the problems that would cause a panel to drop its output within 25-30 years are down to design or manufacture errors.

However, because these errors are covered by the product warranty, many manufacturers will claim that the performance warranty doesn’t cover them.

Aussie consumer law says different, however, because it has something called express warranties.

An express warranty is any promise about a product’s performance – it can be said by a salesperson, or on an advert, or even on a datasheet for a panel; if the customer can reasonably expect a certain performance for 25-30 years, then it’s covered by an express warranty. In Australian consumer law, express warranties have to be honoured.

Remember, the small print can’t deny or refuse what you see in the large print!