Solar panels don't just stop working after their warranty period ends — but understanding how they age helps set realistic long-term expectations.
Most solar panels come with a 25-year performance warranty, guaranteeing a minimum output level (typically 80-88% of original capacity) by year 25. This isn't when panels "die" — it's a guaranteed performance floor. Many panels installed in the 1990s and 2000s are still producing usable power today, well past their original warranty period.
Solar panels experience gradual, predictable efficiency loss over time — typically 0.3% to 0.8% per year depending on panel quality. Premium panels often have degradation rates under 0.4%/year, while budget panels may degrade faster.
| Year | Typical Output (0.5%/yr degradation) |
|---|---|
| Year 1 | 100% |
| Year 10 | ~95% |
| Year 20 | ~90% |
| Year 25 | ~87-88% |
| Year 30 | ~85% |
Inverters: String inverters typically last 10-15 years and often need replacement once during your system's lifetime, at a cost of ,000-,000. Microinverters (installed per panel) often carry 25-year warranties matching the panels themselves.
Racking and mounting: Aluminum racking systems typically last 25-40 years with minimal maintenance.
Batteries (if installed): Typically warrantied for 10 years, with gradual capacity loss similar to any rechargeable battery.
Physical damage (hail, falling debris), manufacturing defects, or simply degrading below a useful output threshold are the main end-of-life factors — not a sudden failure at a specific year. Many panels remain productive for 30-40 years, well beyond their formal warranty period.
If long-term performance matters most to you, look for panels with strong warranties (25+ years), low stated degradation rates, and established manufacturers with a track record — cheaper panels from newer or less established brands carry more long-term risk.
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