Share the math, please? All I've found so far is companies that sell SunPower and compare the SunPower 415 against the Hanwha 315. If SunPower installers need to go to those extremes to make their point, I'm not interested in their pitch.
I see a .25% degradation and an expected 92.7% performance at 25 years for SunPower. That's a good number for anyone who expects solar panels they buy in 2020 to still be on their roof in 2045, or 2040, or even 2030. Solar chemistry is not mature, and my ROI is 6.7 years. When I rip and replace the Hanwha panels in 2030~35, they will have lost 5-7.5%, aka, have 92.5 to 95% of their initial performance. Because my ROI is 6.7 years, I don't really need to think about the panels in their 16th-25th years because they will have been donated to charity by then.
Generally, in any technology that still has innovation velocity, the sweet spot is two to three tiers down from bleeding edge due to propensity to upgrade during the useful life of the product. This is the case with CPUs and video cards. A lot has happened to solar in the past 20 years, and now it's accessible to a scrub like me. But when I look out 10 years, I expect to be able to buy a replacement system with lower cost, more efficiency and less degradation with a short enough ROI that the decision is like buying 4 new tires.