Installation & Warranties
What is the standard degradation rate of solar panels?
Reviewed by SolvSolar · Last reviewed:
Solar panels degrade roughly 0.4–0.55% per year after an initial 1–2% drop in the first year. That means a Tier-1 module still delivers about 87–92% of its rated output at year 25, which is what a linear performance warranty guarantees. TopCon and heterojunction cells sit at the slower end; older polycrystalline modules degrade faster.