Solar TechnologyGlobal
How Long Do Solar Panels Last? Lifespan & Degradation
Solar panels last 25–30+ years, but their output slowly declines. Here’s the realistic picture of lifespan, degradation and what warranties cover.
WaterFuelAndSolarEnergy.com Editorial Team Updated December 2024 6 min read
Residential solar panels are generally designed to last 25–30 years, backed by a 25-year performance warranty that typically guarantees they stay above ~85% of rated output. They don’t “die” — they slowly become less productive.
Degradation rates
Modern panels degrade around 0.3–0.5% per year. After 25 years, a panel rated 400W may still be producing roughly 340–360W. The first year often sees a slightly larger drop before settling into the linear rate.
What affects lifespan
- Heat exposure (hot climates degrade faster)
- Physical damage from weather, hail or debris
- Poor ventilation under the array
- Build quality and materials
Do panels need replacing at 25 years?
No — they keep working, just at reduced output. Many systems run 30+ years. Replace when output no longer meets your needs or economics change.