Solar Panel Degradation Rates: How Much Power Lost?

Last updated: February 1, 2026

Understanding solar panel degradation. Year-by-year output loss, factors that accelerate aging, and which technologies degrade slowest.

Solar panel degradation is the gradual loss of power output over time. In our database of 107 panels, annual degradation rates range from 0.25% to 0.7%. The first year typically sees higher degradation (0.5-2.0%) due to light-induced degradation (LID), after which the rate stabilizes. N-type cells (TOPCon, HJT) degrade significantly slower than P-type PERC cells.

Key Takeaways

• Lowest degradation in our database: 0.25%/year (Maxeon Maxeon 7 470W)
• Highest degradation: 0.7%/year (Renogy 100W Portable Solar Panel)
• First-year degradation: 1-2% (normal LID effect)
• After 25 years: panels retain 80-92% of original output
• N-type panels degrade 30-50% slower than PERC
• Performance warranties guarantee minimum output levels at year 25 and 30

Frequently Asked Questions

What causes first-year degradation?

The higher first-year degradation (typically 1-2%) is called Light-Induced Degradation (LID). When silicon cells are first exposed to sunlight, boron-oxygen defects form that slightly reduce efficiency. This is a one-time effect that stabilizes quickly. N-type cells (TOPCon, HJT) have near-zero LID because they use phosphorus instead of boron.

Can degradation be prevented?

Degradation is a natural characteristic of photovoltaic cells and cannot be prevented entirely. However, choosing N-type panels, maintaining proper ventilation, keeping panels clean, and ensuring quality installation can minimize unnecessary additional degradation. Avoiding hot spots (caused by shading or cracked cells) is the most important preventive measure.