Solar warranties are one of the most misrepresented parts of the buying process. "25-year warranty" sounds reassuring on a quote. The fine print is where it gets interesting.
The three warranty types — they're not the same
Every solar install actually carries three distinct warranties. They cover different things and often have wildly different terms:
- Product warranty — covers panel manufacturing defects. Typically 12–25 years from the manufacturer.
- Performance warranty — guarantees the panel will still produce a minimum % of its rated output over time. Typically 25–30 years.
- Workmanship warranty — covers your installer's labour and the install itself (mounting, wiring, weatherproofing). Typically 2–10 years from the installer.
Where the catches live
The product warranty sounds great until you read what's required to claim. Many manufacturers require professional removal, return shipping, and detailed records of any cleaning chemicals used. Some void the warranty if your installer isn't on their approved list. Some require you to use the same installer for any maintenance for the warranty period to remain valid.
Performance warranties guarantee a minimum output curve — typically 90% in year 10 and 80% in year 25. But manufacturers measure that under specific lab conditions. Real-world degradation rates vary, and proving a shortfall requires expensive testing.
The workmanship warranty is where most installers cut corners. Many quotes will list "25-year warranty" prominently but the installer's own labour warranty is just 2 years. If your roof starts leaking around the mounts in year 6, the panel manufacturer won't help — and a 2-year installer warranty won't either.
What to look for
A genuinely strong warranty package has three things:
- 25-year product warranty from a Tier-1 manufacturer (JA Solar, Aiko, Jinko, REC)
- 25-year performance warranty with a clear degradation curve
- 10-year+ installer workmanship warranty, in writing, with a named guarantor
If your installer can't give you all three, ask why. If they go quiet on the workmanship side, walk away — that's the warranty most likely to actually matter to you in 5–10 years.
The MCS angle
MCS-certified installers carry mandatory installer insurance and a 2-year MCS workmanship guarantee. That's the floor, not the ceiling. The best installers offer 10, 15, or 25 years on top. The cheap ones offer the MCS minimum and hope you don't ask.