NREL has a great report on this [1]. The median degradation is 0.5%, average Si 0.7%, but in their report it could be as high as 4%. Typically, they are quite f

NREL has a great report on this [1]. The median degradation is 0.5%, average Si 0.7%, but in their report it could be as high as 4%. Typically, they are quite fast at the start then slow down as the panel ages. Because they assess the degradation with a 0.5% number and 1.0% is more typical the bell curve moves up. The expectation is P99 [2] which is the question "What is the chance that we see calculated yields exceeds 99% probability?" depends heavily on how the calculation was done in the first place. Some other points mentioned that, wild fires reduces the yields with 6% and hail storms damage the PV systems. Interesting work! Value proposition for PV is lowered by climate change impacts. [1] https://www.nrel.gov/docs/fy12osti/51664.pdf https://www.nrel.gov/docs/fy12osti/51664.pdf [2] https://solargis.com/blog/best-practices/how-to-calculate-p90-or-other-pxx-pv-energy-yield-estimates https://solargis.com/blog/best-practices/how-to-calculate-p9...