[patall]

Why is that always posted without stating the magnitude of the effect? The numbers that you find online are around 15% relative loss at 60°C vs. 25°C panel temperatur (I remember a HN comment reporting 12% comparing peak April to peak July). That is significant, but not world changing, especially for AC.

[Gud]

What about panel degradation?

[defrost]

There are 30 year old still functioning panels in Australia.

Buried in that longevity, is an observation that a fifth of panels degrade faster than expected

  The long tail appears on graphs showing the degradation rate per year of the panels, indicating that up to 20% of all samples perform 1.5 times worse than the average.  

See (Uni NSW study) Cracking the ‘long tail’ problem: new research targets hidden solar panel issue (2026) - https://www.unsw.edu.au/newsroom/news/2026/01/research-targe...

and discussion: Maximising time in the sun: how to maintain and repair solar panels to make them last (2026) - https://www.theguardian.com/australia-news/2026/feb/13/maxim...

This is more about the lifetime of many PV panels in Australia (temps to 45 C so far) not specifically about PV panels with many hours at > 50 C.

[mixermachine]

It exists and does degrade panels but the time horizon is pretty wide. Real world data shows something like 0.5% to 0.7% degregation per year on average. At the start the degregation is higher and but it slows down with age.

So a 20 year old panel might be at around 80% in the worst case. Often they are in much better shape. This seems like a pretty good deal to me.