Degradation Rate

Degradation rate is the small annual loss of a panel’s output over its life, warranted at roughly 0.40–0.55% per year for current technology. A quality panel still delivers 85–90% of its original output after 25 years.

The performance warranty documents this as a year-by-year guaranteed output curve ("linear warranty"). First-year degradation (LID/LETID) is slightly higher and is also capped in the warranty of reputable manufacturers.

Part of the HUM Solar Glossary — 75+ plain-language definitions for India’s solar ecosystem, maintained as a neutral reference. Browse all terms →