How long do solar panels last?
Solar panels last 25 to 30 years or more. They do not stop working — they slowly lose output, typically about 0.5% a year, so a panel still produces roughly 85–88% of its original power at year 25. The inverter is what usually fails first, around year 12–15.
What degradation actually looks like
| Year | Output remaining | Notes |
|---|---|---|
| 1 | ~98% | Small initial drop in the first months, then it settles |
| 10 | ~93% | Usually still comfortably inside warranty |
| 25 | ~86% | End of typical performance warranty |
| 30+ | ~83% | Still generating; many 1990s arrays are still running |
Two warranties, and they are not the same
- Product warranty — covers manufacturing defects and physical failure. Typically 12–25 years.
- Performance warranty — guarantees output stays above a stated curve, usually ~85–87% at year 25.
A long performance warranty is worth little if the product warranty is short, and both are worth nothing if the manufacturer folds. Prefer established manufacturers over headline warranty numbers.
The inverter is the real consumable
What actually kills panels early
- Bad installation — the single most common cause. Poor flashing leaks; poor wiring corrodes.
- Hail — panels are tested to withstand roughly 25mm hail at 80 km/h. Severe storms exceed that.
- Micro-cracks from walking on panels or careless handling during install.
- Delamination from moisture ingress, usually a manufacturing defect that appears within a decade.
What this means for the maths
Our estimates model 25 years because that is the warranted life. In practice most arrays keep producing well past it, so a system that pays back in 9 years plausibly delivers 20+ years of near-free electricity. How payback works →
What this looks like in real cities
Measured rooftop data, spanning the range from fastest to slowest payback we have found:
| City | Sun hrs/yr | Rate | Payback |
|---|---|---|---|
| Honolulu, HI | 1,787 | 42.1¢ | 3.1 yrs |
| Plano, TX | 1,765 | 15.1¢ | 8.8 yrs |
| Alexandria, VA | 1,527 | 14.2¢ | 10.9 yrs |
| Aylesbury, South East | 1,008 | 26.1¢ | 12.9 yrs |
| Gatineau, QC | 1,291 | 7.9¢ | 33.3 yrs |
Frequently asked
Do solar panels stop working after 25 years?
No. Twenty-five years is the typical performance warranty, not a lifespan. Panels degrade slowly, around 0.5% a year, so a well-installed array is often still producing 80% or more of its original output after a quarter century. Inverters get replaced long before the panels do.
What is the most common solar failure?
Inverter failure, by a wide margin. Inverters handle constant conversion and heat, and typically last ten to fifteen years against the panels' twenty-five plus. Beyond that, most problems are installation faults — poor flashing, loose connections or bad wiring — rather than defects in the panels themselves.
Does hot weather shorten panel life?
Sustained heat reduces output on the day and adds long-term stress, but it does not dramatically shorten life. Panels lose efficiency as cell temperature rises, which is why a very hot sunny region can produce slightly less than its sunshine hours alone suggest. Good airflow behind panels helps.
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General information, updated 2026-08-22. Not financial, tax or engineering advice.