Modern solar panels last 25 to 30+ years, and most come with a 25-year performance warranty. They don’t suddenly stop working at year 25 — they slowly produce a little less each year. Here’s exactly what to expect over a system’s life.
The 25-year warranty isn’t an expiration date
When manufacturers warranty panels for 25 years, they’re guaranteeing a minimum output level, not the end of the panel’s life. A typical warranty promises the panels will still produce at least 85–87% of their original output after 25 years. Many panels keep generating useful power well into their 30s.
How degradation works
Solar panels lose a small amount of output every year — this is called the degradation rate.
- Typical degradation: about 0.5% per year for quality modern panels (premium panels can be 0.25–0.4%).
- Year 1: there’s often a slightly larger initial drop (~1–2%), then it settles into the steady ~0.5% annual decline.
| Year | Approx. output (at 0.5%/yr) |
|---|---|
| 1 | ~99% |
| 10 | ~95% |
| 20 | ~90% |
| 25 | ~88% |
| 30 | ~85% |
So a 25-year-old panel still cranks out roughly 88% of day-one production — which is why our savings calculator models a full 25-year horizon with degradation built in.
What actually wears out first
The panels themselves are the most durable part (no moving parts, sealed glass). The components more likely to need attention:
- The inverter — the part that converts DC to usable AC. String inverters often last 10–15 years, so you may replace one once during the system’s life (budget ~$1,000–$2,000). Microinverters and many hybrid inverters carry longer 20–25 year warranties.
- Mounting hardware and wiring — rarely an issue, but flashing/seals are worth checking if your roof is re-done.
- Batteries (if you have storage) — typically warrantied 10 years.
How to make panels last longer
Solar is famously low-maintenance, but a few things help:
- Keep them reasonably clean. Rain handles most of it; an occasional rinse helps in dusty or pollen-heavy areas.
- Keep them unshaded. Trim trees that grow into the array’s sun.
- Monitor production. Most systems include an app — a sudden drop flags an inverter or panel issue early.
- Choose quality equipment and a reputable installer. The warranty is only as good as the company behind it.
Does the long lifespan change the math?
It improves it. Because panels keep producing for years after they’ve paid for themselves, most of the system’s lifetime savings come in the back half of its life — essentially free electricity once the payback point passes (often around 6–10 years).
Bottom line
Expect 25–30+ years of useful production, with output gently declining about 0.5% a year to ~85–88% by year 25. Budget for one possible inverter replacement, keep the array clean and unshaded, and the panels will quietly pay you back long after they’ve covered their cost. See what that looks like for your home with the solar savings calculator.
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