How Long Do Solar Panels Last?
The short answer: most solar panels are warrantied to produce for 25–30 years, and they keep producing at reduced output for 40 years or more. Panels rarely "die" on a schedule; they slowly fade. So the number that matters when you ask how long panels last is not an expiry date; it is the degradation rate: roughly 0.25% of output lost per year for premium panels, 0.5% for standard, and 0.75% for budget. Here is what that math does over 25 years, what $5,285 real panel warranties look like, and how to decide when replacement is justified.
Degradation curves: the real lifespan math
Solar panels lose a small, predictable slice of their output every year. The industry splits roughly into three tiers — the same tiers our PV Degradation Projector uses when it models 25-year production: premium panels at 0.25% per year, standard at 0.50%, and budget at 0.75%. Compounded to year 25, here is what survives of year-1 output:
| Tier | Degradation / yr | Year-25 output (% of year 1) |
|---|---|---|
| Premium | 0.25% | 94.2% |
| Standard | 0.50% | 88.7% |
| Budget | 0.75% | 83.5% |
Read that table as the honest version of "how long do panels last." A premium system chugging along at 94.2% of day-one output in year 25 is not at end of life — it is a slightly smaller power plant. The same holds for a standard-tier system at 88.7%. Even budget panels at 83.5% are still producing more than four-fifths of their original power.
The other number to know is the warranty threshold: most manufacturers guarantee panels will not degrade faster than about 0.7%/yr on a linear basis — which works out to roughly 84.5% of rated output at year 25. A panel degrading faster than that line is not "old" — it is a warranty event, and you should be claiming it, not replacing it. Want to see your own system's curve? The PV Degradation Projector runs this exact math on your year-1 production, tier, and electricity rate.
Warranty reality: what the database shows
Talk is cheap, so we went to the data: our panel database tracks 5,285 panel models across 42 brands, each with its published warranty term. Here is the full distribution of warranty lengths (panel-model warranty terms, last updated 2026-08-06):
| Warranty length | Panels in database | Share |
|---|---|---|
| 25 years | 2,708 | 51.2% |
| 30 years | 1,159 | 21.9% |
| 12 years | 786 | 14.9% |
| 17 years | 331 | 6.3% |
| 40 years | 200 | 3.8% |
| 10 years | 58 | 1.1% |
| 35 years | 33 | 0.6% |
| 15 years | 10 | 0.2% |
| Total | 5,285 | 100% |
Two things jump out of that distribution. First, the dominant cluster: 2,708 models at 25 years and 1,159 at 30 years — together 73% of the database. Those are performance warranties, guaranteeing a minimum output level for decades. Second, the 10–17 year cluster is not a contradiction — it reflects product/parts warranties, which cover defects and workmanship and typically run much shorter than the performance guarantee. When a manufacturer quotes "25-year warranty," read the fine print to learn which of the two they mean. And yes, 200 models now carry 40-year warranties — the high end of the market has stopped pretending panels die at 25.
Does the brand matter? What the data says
Brand snobbery is easy; here is what tier correlates with in the database. Of 5,285 models, 1,760 are classed premium, 3,105 standard, and 420 budget. The pattern: premium panels pair the tightest degradation (0.25%/yr) with the longest warranty terms, and that is what you are paying for. Budget panels at 0.75%/yr still work fine; they surrender roughly 11 percentage points more output by year 25, which compounds into measurably lower lifetime kWh.
One honesty note the data also enforces: brands themselves have lifespans. 200 SunPower models in the database are flagged discontinued — SunPower ceased operations (Chapter 11 bankruptcy, August 2024) — a reminder that a 40-year warranty is only as strong as the company behind it. Browse the full brand directory or compare specific models side by side in the Panel Comparison tool.
When to replace vs. when to keep
Use a decision framework, not a birthday calendar:
- Keep the system if output is still above the warranty threshold line (~0.7%/yr linear) and the array still offsets a meaningful slice of your bill. Slow, boring degradation is the system working as designed.
- Claim warranty — not replace — if measured degradation beats the guarantee line. That is what the performance warranty exists for.
- Repair first when something breaks: inverter failures dominate real-world service calls, and inverters are replaceable components, not a reason to pull panels.
- Replace (or at least re-evaluate) when a roof replacement forces a remove-and-reinstall decision anyway, or when an aging, undersized system no longer covers a bill that rate increases have inflated.
For the economics of that last decision, run your actual numbers — and run them without assuming a federal credit: the 25D residential credit expired December 31, 2025, and the Section 48E credit only reached lease/PPA and commercial projects that began construction before July 4, 2026 (that deadline has passed; grandfathered systems must be in service by December 31, 2027). The Solar System Size Calculator and the state-by-state payback pages do this math with your real rate and sun hours.
Project YOUR system's year-25 output
Enter your system size, tier, and year-1 production — the PV Degradation Projector charts the full 25-year curve against the warranty threshold and shows what each year's output is worth at your electricity rate.
Run the Projection →Questions homeowners ask most
How long do solar panels last in practice?
What is a solar panel degradation rate?
Do solar panels stop working after 25 years?
What does a solar panel warranty cover?
When should I replace my solar panels?
"How long do solar panels last" is really "how fast do they fade." Warranties promise 25–30 years of output, the data shows 73% of 5,285 models carrying exactly that, and the physics says most keep producing for decades past the paperwork. Watch the degradation curve, not the calendar.