In one line
Annual loss of power output from a solar module due to material aging, typically 0.4–0.7% per year for 2026 modules.
What it means
Solar modules lose output capacity over time. 2026 Tier 1 TOPCon and HJT modules typically warranty 87–90% of nameplate at 25 years (equivalent to 0.4–0.5% annual linear degradation). Real-world fleet data shows median degradation closer to 0.5%/year, with outliers driven by hot climates, PID (potential-induced degradation), and manufacturing defects. Degradation is the single biggest assumption in 25-year solar LCOE calculations.
Related terms
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