I really like it for two things first It could be another radicalization vector for people inside not that radical movement's like some parts of the climate movement. And second it gives me and my comrades a vision and a world to fight for. There is a reason that optimism stands in the two first lines inside the Solarpunk manifesto.

We are solarpunks because optimism has been taken away from us and we are trying to take it back.

We are solarpunks because the only other options are denial or despair.

Also you are completely right with it being Anarchist:

At its core, Solarpunk is a vision of a future that embodies the best of what humanity can achieve: a post-scarcity, post-hierarchy, post-capitalistic world where humanity sees itself as part of nature and clean energy replaces fossil fuels.

There’s a lot of overlap with lots of schools of anarchy. I think lots of the “punk” movements have been like that though.

a desirable vision is needed.

Solarpunk could've been an update to stale sub-ideologies of Anarchism.

In online communities Solarpunk unfortunately is associated with greenwashing soil sealing, motorised individual transport and nuclear industry and others. This status makes it a product of climate delay propaganda currently and thus unusable.

I love the aesthetic and ideas, but personally I couldn't get into it that much. It ~~seems~~ feels too unrealistic and a little like greenwashing (renewable energy and other high-tech is core to the ideology).

A book featuring the style which I really liked was A Psalm for the Wild-Built.