How long do solar panels and inverters actually last?

The two components age very differently, and understanding that avoids both false economy at purchase and unpleasant surprises at year eight.

Panels

Panels have no moving parts and degrade gradually rather than failing. Manufacturers typically warrant a percentage of original output at 25 years, with a separate and much shorter product warranty covering defects. Australian conditions, particularly heat, are hard on them, and mounting quality matters as much as the panel brand for how they survive.

Inverters

The inverter is electronics working hard every day, usually outdoors. String inverter warranties are commonly five to ten years with the option to extend, and replacement during the system's life should be treated as expected rather than as a failure. Microinverters and optimisers distribute this differently, with longer warranties but more units to fail.

What to check before buying

• Whether the manufacturer has an Australian presence, because a warranty from an entity with no local operation is difficult to claim on.
• Whether the warranty covers labour and access, or only the part. Removing and refitting a roof-mounted component is most of the cost.
• The installer's own workmanship warranty, which is separate from the product warranties and is what covers mounting, flashing and cabling.
• Whether the roof itself has enough remaining life. Removing and refitting an array to replace a roof is an expensive way to learn this.