The short answer
Solar panels are long-lived. Modern panels typically carry a performance warranty of around 25 years and commonly keep generating beyond that, often for 30 years or more, with output slowly declining over time. Panels degrade gradually — typically a fraction of a percent per year — so a panel still produces the large majority of its original output decades in. The shorter-lived component is usually the inverter, which often lasts around 10–15 years and may need replacing once during the system's life. A home battery, if fitted, is generally warrantied for around 10 years. So the panels themselves are a multi-decade asset; the practical maintenance event most homeowners should expect is a single inverter replacement.
Solar panels outlast most other home equipment. The useful distinction is between the panels (very long-lived) and the supporting components like the inverter (replaced once or so over the system's life).
Solar lifespan
- Panel performance warranty~25 years
- Panels often keep working30+ years
- Degradation rateA fraction of a percent per year
- Inverter lifespan~10–15 years
- Battery warranty~10 years
How long the panels themselves last
The solar panels are the most durable part of the system. They have no moving parts, sit out in the weather and are built to last decades:
- Performance warranty: manufacturers typically guarantee panels will still produce a stated percentage of their original output after around 25 years. This is a warranty on performance, not a use-by date.
- Often longer in practice: many panels keep generating well beyond their warranty period — frequently 30 years or more — just at a gradually reduced output.
- Slow degradation: panels lose a small fraction of their output each year (degradation). After 25 years a typical panel still produces a large share of its original output. The decline is steady and predictable rather than sudden.
Because the panels are so long-lived, the system's overall lifespan is usually limited by the supporting components rather than the panels themselves.
Lifespan of each component
A solar system is more than the panels. Each part has its own expected lifespan and warranty, summarised below.
| Component | Typical lifespan | Typical warranty | Notes |
|---|---|---|---|
| Panels | 25–30+ years | ~25 years (performance) | Slow degradation; very durable |
| Inverter (string) | ~10–15 years | Often 5–12 years | May need replacing once |
| Microinverters/optimisers | Often longer than string | Can be longer | Mounted at each panel |
| Battery | ~10 years | ~10 years | Capacity fades over cycles |
| Mounting/wiring | Very long | Workmanship guarantee | Minimal wear |
Indicative lifespans for guidance. Sources: Energy Saving Trust; MCS. Actual figures depend on the product, installation quality and conditions.
What to expect over the system's life
Putting the components together, here is the realistic long-term picture for a UK home:
- Panels are a set-and-forget asset: once installed, the panels need little attention and keep generating for decades with slowly declining output. There is no routine part to replace on the panels themselves.
- Expect one inverter replacement: the inverter is the component most likely to need replacing during the system's life, often after 10–15 years. Budgeting for one inverter swap over a 25-year-plus life is sensible.
- Batteries are a separate lifecycle: if you have a battery, it is generally warrantied for around 10 years, with capacity gradually fading as it cycles. A battery may be replaced or upgraded before the panels reach the end of their life.
- Degradation is gradual: the slow annual decline in panel output is already accounted for in long-term generation and payback estimates, so it does not come as a surprise.
Because typical payback is in the region of 7–12 years and the panels last 25 years or more, a well-installed system spends most of its life in the period after it has paid for itself. The main long-term cost to plan for is the inverter; the panels themselves keep working long after they have repaid their cost.
Frequently asked questions
Do solar panels stop working after 25 years?
No. The 25-year figure is usually a performance warranty — it guarantees the panel will still produce a stated percentage of its original output at that point, not that it stops. Many panels keep generating for 30 years or more beyond installation, simply at a gradually reduced output as they slowly degrade.
How often do you need to replace a solar inverter?
The inverter is the component most likely to need replacing during a system's life, typically after around 10 to 15 years. Most homeowners should budget for one inverter replacement over a 25-year-plus system life. Panels themselves are far more durable and rarely need replacing within that period.
How much do solar panels degrade each year?
Panels degrade slowly — typically a fraction of a percent of output per year. The decline is steady rather than sudden, so after 25 years a typical panel still produces the large majority of its original output. This gradual degradation is already factored into long-term generation and payback estimates.
Sources & further reading
Figures on this page are typical UK ranges drawn from published sources and depend on your specific home. They are guidance, not a quotation or guaranteed saving.