Solar Panel Warranties Explained

Product warranty

Covers manufacturing defects in the panels themselves. Lengths vary considerably between manufacturers, so compare like for like.

Performance warranty

Panels degrade slowly over time. A performance warranty guarantees the panel will still produce at least a stated percentage of its original output after a set number of years — commonly around 25.

Inverter warranty

Usually shorter than the panel warranty, and important because the inverter is the component most likely to need replacing. Ask whether an extended warranty is available and what it costs.

Workmanship warranty

This is the installer’s own guarantee covering the quality of the installation — including roof weatherproofing. It is only as good as the company standing behind it.

Insurance-backed guarantees

Some installers offer insurance-backed guarantees so cover continues if the company ceases trading. Worth asking about, particularly with newer firms.

What to check before signing

• Are all four warranties stated in writing?
• Who do you contact for a claim — installer or manufacturer?
• Is the installer MCS-certified?

This article is general information. Costs and savings vary by property, energy use and tariff.