Warranty documents describe a straightforward remedy. The practical experience of claiming is less straightforward, and the difference is mostly about evidence and about who pays for the parts a warranty does not cover.
Owners often treat this as one thing. It is three, with different parties and different terms.
Product warranty from the module manufacturer, covering manufacturing defects. Typically 10-15 years, some now 25.
Performance warranty from the same manufacturer, guaranteeing output degrades no faster than a stated curve. Typically 25-30 years.
Workmanship warranty from the installer, covering installation quality. Typically 2-10 years and highly variable.
A failing module might be any of these. A module cracked by someone walking on it during installation is workmanship. A module with a manufacturing defect is product. A module producing 12% below curve in year eight with no visible fault is performance. Determining which comes first, and the parties have differing views.
Almost universally excluded:
For a single module this is a nuisance. For a systematic defect affecting hundreds of modules, the uncovered labour and access cost can approach the value of the modules themselves.
Manufacturers require documentation, and the requests are reasonable but hard to satisfy retrospectively:
The clamping zone requirement catches people. Manufacturers specify where on the frame clamps may be placed. Clamping outside those zones can induce stress and crack cells – and if your installer did that, the manufacturer will decline the claim, correctly. Photographs from installation showing correct clamping are worth having.
Proving a module has degraded faster than its warranty curve requires measuring individual module output under controlled conditions and comparing against the curve, accounting for irradiance, temperature and soiling.
That usually means a specialist testing exercise. Manufacturers may require testing at an accredited laboratory, which means removing sample modules and shipping them.
The cost of establishing the claim can be significant relative to the value recovered, which is precisely why performance warranties are less often claimed than their prominence in sales material suggests. This is worth knowing when someone presents a 30-year performance warranty as a major selling point.
A warranty is worth what the entity behind it is worth. Module manufacturers exit markets and occasionally fail. If the warrantor is a national subsidiary with minimal assets rather than the parent, enforcement may be difficult.
Warranty insurance products exist, backing manufacturer obligations with an insurer. Where available for the product you are buying, they meaningfully improve the position – ask whether the manufacturer offers it.
An afternoon at handover. It is the difference between a claim that proceeds and one that becomes a negotiation you are poorly positioned for.