Warranties are one of the most misrepresented parts of buying solar. "25-year warranty" looks good on a quote. The fine print is where it gets interesting.
The three warranty types aren't the same
Every solar install carries three distinct warranties. They cover different things and often have very 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 a claim requires. 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 all maintenance during the warranty period.
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. Degradation on a roof varies, and proving a shortfall needs expensive testing.
The workmanship warranty is where most installers cut corners. Many quotes list "25-year warranty" prominently while the installer's own labour warranty is only 2 years. If your roof starts leaking around the mounts in year 6, the panel manufacturer won't help, and neither will a 2-year installer warranty.
What to look for
A strong warranty package has three things:
- 25-year product warranty from a Tier-1 manufacturer (DMEGC, Aiko)
- 25-year performance warranty with a clear degradation curve
- An insurance-backed workmanship guarantee (IBG), in writing, naming the insurer or scheme
If your installer can't give you all three, ask why. Ask who insures the workmanship guarantee. That's the warranty most likely to matter to you in 5–10 years.
The insurance-backed guarantee
MCS-certified installs must come with an insurance-backed guarantee. Ask each installer how long their protection lasts, what it covers and who insures it.
