New panels and inverter ordered!

[openspaceman]

Yes I looked up Airy point after you first mentioned it

[AE-NMidlands]

I looked up Airy point on wikipedia and learnt about another one too! I'm not sure it is the most relevant dimension, because stopping wind getting under and lifting the edge of panels (and snapping them) must be important.
I would think that 3 carefully adjusted mountings on each of 2 sides or at 2 points on all 4 sides would be the winners.
A

[Oldgreybeard]

If you look at the forces involved and then calculate the stress in the panel and frames, they aren't massive, TBH. Snow loading could be around 500N/m² for areas of the UK where snowfall rarely exceed 100mm, with panels pitched at 45°. Wind loading is really the main issue I think, because it will act in both directions and create loads that reverse direction quite rapidly in gusts.

The suction on the upper face of an inclined panel (from lift) is hard to quantify, but it will be proportional to the square of the wind speed, so in exposed areas I think that load could be quite high, probably a fair bit higher than the snow loading. I doubt that the glass in panels is subject to stress-related weakening over time, but the frames almost certainly are, so anything that reduces the stress in the panel as a whole seems like a good thing.

All the roof and ground mount panel installation instructions seem to show fixings that are more or less at the Airy points, with rails running part way in from each panel edge. I doubt the spacing is that critical, TBH, just having supports in from the edge a bit is enough to significantly enhance the security of the mounting. I could model it, but the panel manufacturers don't seem to provide that level of detail of their panel dimensions and construction materials. Not too bothered for this walkway canopy, as it's a very sheltered location, well out of the prevailing wind and we rarely ever get snow here (cue the worst winter Dorset has ever seen . . .).