Land currently used to grow biofuels might be a better place to start, although I agree that re-wilding it would be better still.

I'm also not sure that the availability or cost of panels is the limiting factor for there being some in a field somewhere *as well* as here. Availability of labour to install them could be though.

You can see inset access panels in the cross members which suggests that the securing bolts are hidden but accessible, which tells me that effort was applied to hiding the fasteners, which implies that someone spent a lot of time on the visual impact of those beams.

Could be they aren't actually solid glulams, but boxed trim over skinny beams.

Possibly box section beams? For aesthetics? Otherwise the front curtain construction looks like mostly dead weight.

All in favour of using wood though.

This is exactly how it should be done, and preferably those are double sided so that they can also produce electricity from light reflected from the platforms