In your opinion, what’s a good example of a well written Solarpunk story? How about another one that is at least well known in pop culture?

I’d say “Nausicaä of the Valley of the Wind” could be one good example. Perhaps a little more post-apocalyptic, but it’s got all the markings of positive change, societal sustainability, and environmentalism, along with futuristic sci-fi world building. Both the anime and manga are fantastic, but I guess not too prominent in Western pop culture.