That's a great catch ! Thanks for this. For anyone wondering, 25 years is pretty common as a baseline for PV [1] but a good amount of them should be able to go for longer, say at least 30 years. As a comparison, the average nuclear power plant in France is 37 years old, and the french authority considers obvious a 50 year life expectancy, and 60 is being floated [2], but no idea where they got 80 from probably from the US extensions being floated [3] — 92% capacity factor are official measurements though, it's not unrealistic [4]
And it's not like solar panels stop working at 25 years. The biggest reason to replace solar panels at 20 years or so is that new panels are so much better than old ones. If technological process stopped we'd keep panels for longer.
One aspects to consider I think could be damage from external sources. Like freak hail storms that could be more common. If these sort of events regularly destroy panels with other accidents like fires due to failing installations average age could drop even if some panels are still functional.
Outside most extreme events nuclear plants in general are repaired if some component fails.
A freak hailstorm could take an entire solar farm out, but otherwise they are pretty resilient. There are pictures of Ukrainian solar installations that continue operating after missile strikes. The panels that got hit stop working, but the rest keep supplying power.
Folk in my area replaced panels on their 15yr old install. I didn't get hard metrics from them but, they said it's worth it. Got some state provided rebate too.
