Solar panels last 25 to 30 years. Most warranties cover that range - after which output may have dropped by 10 to 15% from new. The panels don't stop working at year 25. Many systems from the 1990s still generate electricity today.
The UK climate suits solar longevity. Cooler temperatures reduce heat degradation, and the weather causes less physical wear than harsher climates.
Popular Brands and Their Warranties (2026)
| Brand | Product Warranty | Performance Warranty | Max Efficiency | Notes |
| Project Solar | Lifetime | Lifetime | 25.5% | Only brand offering lifetime warranties |
| SunPower Maxeon | 40 years | 40 years | 22.8% | Longest fixed warranty on the market |
| Perlight | 30 years | 30 years | 23.2% | Strong value for warranty length |
| JinkoSolar Tiger Neo | 25 years | 30 years | 24.8% | 87% output retained after 30 years |
| LONGi Hi-MO S10 | 25 years | 30 years | 25.0% | 88% output retained after 30 years |
| AIKO Neostar | 15 years | 30 years | 24–25% | Shorter product warranty, strong performance |
| REC Alpha Pure-R | 25 years | 25 years | 22%+ | Low degradation rate |
| JA Solar DeepBlue | 15 years | 25 years | 22.5% | Best value option |
| Qcells Q.TRON | 25 years | 25–30 years | 21–22% | Reliable mid-range choice |
| Panasonic EverVolt | 25 years | 25 years | 21–22% | Established brand trust |
What Happens After 25 Years?
Output drops gradually. High-quality panels degrade at around 0.4 to 0.5% per year — after 25 years they're producing around 87 to 88% of their original output. That's still a meaningful amount of free electricity.
The warranty stops at year 25 or 30. The panels don't.
What Causes Panels to Degrade?
UV exposure. UV radiation slowly breaks down materials inside the cell over years. Premium monocrystalline cells hold up better than cheaper options over long periods.
Temperature cycling. Panels expand and contract as they heat and cool each day. Panels built for temperature fluctuation handle this without issue in normal UK conditions.
Physical damage. Standard UK weather rarely causes serious damage. Panels are rated to withstand wind, rain, and hail. Heavy snowfall in exposed locations adds load stress, though most panels are rated to 5,400Pa. Falling branches and unusually large hail are the more realistic risks.
Poor installation. Panels installed without proper ventilation, incorrect wiring, or inadequate mounting age faster. MCS-certified installation matters for longevity, not just compliance.
Output Drops Before Year 15 — What to Check
A sudden drop in output before 10 to 15 years is not normal degradation. Check these first:
Dirt and debris. Bird droppings, dust, and leaf build-up block sunlight. A clean can recover several percent of lost output quickly.
Shading changes. Trees grow. New buildings appear. Check whether something now casts shadow on panels that weren't shaded at installation.
Inverter failure. Inverters need replacing after 10 to 12 years. A failing inverter reduces output even when panels are working fine.
Wiring faults. A loose connection or corroded junction box can significantly cut generation. Most monitoring apps flag unusual drops automatically.
If the cause isn't clear, book a maintenance check. If the system is within warranty, the manufacturer covers qualifying repairs and replacements.
Three Things That Extend Panel Life
Buy quality panels. A premium panel degrading at 0.4% per year retains considerably more output at year 25 than a budget panel at 0.8%. The difference compounds over decades.
Use an MCS-certified installer. Correct ventilation, secure mounting, and quality electrical connections make a direct difference to long-term performance — and keep your warranty valid.
Monitor and clean regularly. Two to three cleans per year keeps output up. Check your inverter app monthly. Catching small issues early prevents bigger ones.
A professional check every few years is worth scheduling — particularly around year 10 to 12 when inverters are approaching end of life.
Do Different Panel Types Last Longer?
Monocrystalline panels degrade more slowly than polycrystalline and have longer track records. They're the standard for UK homes in 2026.
N-type monocrystalline panels — used in AIKO, LONGi Hi-MO S10, JinkoSolar Tiger Neo, and others — degrade more slowly still. They're also less prone to light-induced degradation in the first weeks after installation. For a system you plan to run for 30 years, N-type is worth the slightly higher upfront cost.
Understanding Your Warranty
Product warranty covers manufacturing defects and physical failures — delamination, frame failure, cracked cells. This runs 12 to 25 years depending on brand.
Performance warranty guarantees the panel hits a minimum output percentage each year — 98% in year one, dropping by 0.4 to 0.5% annually. If your panel falls below the guaranteed threshold, the manufacturer covers the difference.
Read both documents before buying. Some brands offer a 25-year performance warranty but only a 10-year product warranty, meaning a physical failure in year 15 isn't covered. The product warranty is the shorter and often more limited of the two — check it carefully.
Get a Quote from CRG Direct
CRG Direct installs across Hampshire, Guildford, and the South Coast. Every installation is MCS-certified and uses panels from brands with strong warranty track records.