I'd argue that both Black Panther films fall within solarpunk (at least when it comes to Wakanda--which, yes, I know that it is also afrofuturism, but there's clear overlap at times). And both films deal with "negative" elements: isolationism in service of creating a paradise and monopolizing the technology that makes such a paradise possible are themes in both of the films and which could be further explored in other solarpunk fiction.