# Panel degradation rates are quietly improving — warranties haven't caught up

> Field data shows top-tier panels degrading slower than their own warranty documents assume.

- URL: https://solarexaminer.com/posts/panel-degradation-warranty-report/
- Site: Solar Examiner (https://solarexaminer.com/)
- Category: Equipment
- Published: 2026-08-30
- Author: Priya Nathan


Most 25-year panel warranties still guarantee output based on degradation assumptions written a decade ago — roughly 0.5% annual loss. Independent field data we reviewed from installations five to twelve years old shows top-tier monocrystalline panels degrading closer to 0.3% annually.

This matters for payback calculations more than it sounds: over 25 years, that difference compounds to roughly 4-5 percentage points of additional lifetime output that most solar calculators don't credit you for, because they use the conservative warranty number by default.

Image credit: Photo by Chirayu Trivedi on [Unsplash](https://unsplash.com/photos/a-large-amount-of-solar-panels-on-the-roof-of-a-building-twOIx6I35tk?utm_source=solarexaminer&utm_medium=referral)