Solar Panel Degradation — Annual Output Loss
Published 2026-02-20 · Updated 2026-07-07 · MySunROI Research Team
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Solar panels lose ~0.5% output per year on average. A 10 kW system producing 14,000 kWh in year 1 may produce ~12,500 kWh in year 25 — still profitable after payback.
Degradation rates
Tier-1 panels: 0.4–0.55%/year. Premium (Maxeon): ~0.25%/year.
Modeling 25-year savings
Good calculators account for degradation and rate inflation.
Solar costs by state
Frequently Asked Questions
Is 0.5%/year a lot?
No — payback happens years before degradation becomes significant.