@spinflip@qoto.org Solarpunk is largely a reaction to dystopian visions of the future. Instead of a Bladerunner-esque world of pollution and corporate greed, solarpunk envisions a sustainable non-exploitative future.
Broadly, I'd say the largest underlying theme is a desire for harmony and unity – between technology and nature, and between different people.
There still isn't much literature yet, but a story anthology called Sunvault was recently published... https://www.goodreads.com/book/show/35235851-sunvault