How Long Do Solar Panels Last? Lifespan & Degradation
Table of contents
How long do solar panels last?
Most quality solar panels are built to last 25 to 30 years, and often longer. That figure is not the point at which they stop working — it is roughly the warranty horizon and the age by which output has faded enough that replacement starts to make sense. Plenty of panels installed in the 1990s are still generating today, just at a reduced level.
So the honest answer has two parts: the panels keep producing for decades, but they slowly produce a little less each year. Understanding that slow fade — and what speeds it up — is the key to knowing what to really expect.
Degradation: what "losing power" actually means
Panels lose output through degradation, a gradual decline caused by sun, heat and weather cycling. Modern panels degrade at roughly 0.4–0.5% per year, sometimes less for premium modules. The first year usually sees a slightly larger drop as the cells settle, then the decline is steady and predictable.
The math is reassuring. At 0.5% a year, a panel still delivers about 90% of its original output after 20 years and around 85–88% after 25. The chart below shows the typical curve.
Illustrative at ~0.5%/year degradation: a panel still produces around 85–88% of its original output after 25 years.
| Years | Output retained (%) |
|---|---|
| 0 | 100 % |
| 5 | 97 % |
| 10 | 95 % |
| 15 | 92 % |
| 20 | 90 % |
| 25 | 87 % |
Source: NREL — PV degradation rates
This is why "the panels are old" rarely means "the panels are dead." A 20-year-old array producing 90% of nameplate is still doing its job — it just gives you a little less headroom than the day it was installed.
What shortens — or extends — panel life
Build quality and conditions both matter:
- Heat is the biggest accelerator. Panels in very hot climates degrade a touch faster than those kept cooler, which is why good mounting that lets air circulate behind the modules helps.
- Quality tier matters: reputable manufacturers with low degradation rates and strong warranties outlast bargain panels.
- Weather extremes — hail, heavy snow load, salt air near coasts — stress the laminate and frame over time.
- Installation is underrated: poor mounting, micro-cracks from rough handling, or a leaky roof penetration shorten real-world life more than sunlight ever will.
Good maintenance — mostly just monitoring and the occasional clean — protects that lifespan without much effort.
Warranties: product vs performance
Solar warranties come in two flavours, and buyers often confuse them:
- Product (workmanship) warranty covers defects in the panel itself — typically 12 to 25 years depending on the brand.
- Performance (power) warranty guarantees a minimum output over time — commonly around 85–90% at year 25.
A strong warranty is one of the clearest quality signals you can read off a spec sheet. Two panels at the same price with a 12-year vs a 25-year product warranty are not the same purchase.
The other components
The panels usually outlast everything else in the system. The inverter is the part most likely to need replacing first — string inverters often last 10–15 years, while microinverters carry longer warranties. Budget for at least one inverter replacement over the life of the array, and treat it as normal rather than a failure.
What happens at end of life
When a panel finally retires, it is largely recyclable — glass, aluminium frame and silicon can be recovered. End-of-life volumes are still small today but growing, and recycling infrastructure is expanding. We cover this in detail in solar panel recycling.
FAQ
Do solar panels stop working after 25 years? No. 25–30 years is the warranty horizon, not a cliff. Panels keep producing afterwards, just at a gradually reduced output.
How much output do panels lose each year? Typically about 0.4–0.5% per year, so roughly 85–90% of original output remains after 25 years.
What fails first, the panels or the inverter? Usually the inverter. String inverters often last 10–15 years, so plan for at least one replacement.
Does heat shorten panel life? Yes, slightly. Hotter climates see marginally faster degradation, which good airflow behind the panels helps offset.
Getting the most life from your array
A few habits stretch a system's productive years without much effort:
- Monitor output so a failing panel or inverter is caught early, rather than silently dragging down production for months.
- Keep panels ventilated and unshaded — trapped heat and creeping tree shade are slow, avoidable losses.
- Use a reputable installer: clean wiring, proper flashing and careful handling prevent the micro-cracks and roof leaks that cut life short.
- Service the inverter instead of ignoring it; it is the component most likely to need attention before the panels do.
None of this is demanding, and together it keeps an array close to its theoretical lifespan.
Bottom line
Expect a quality solar array to produce for 25–30 years or more, losing only about half a percent of output a year. The panels rarely fail outright; you will likely replace an inverter once, clean occasionally, and watch output fade slowly and predictably. Choose panels with low degradation and a long performance warranty, and the system will quietly outlast most other things on your roof. See also panel efficiency and monocrystalline vs polycrystalline.
Last updated June 2026. Informational only — check the specific product and performance warranties on any panel you are quoted.