What I like about solarpunk is that it's utopia without the utopia part. Remember when people like Zizek were complaining that in our postmodern era it's all about coffee without caffeine, sweet stuff without sugar, etc? Well, solarpunk is exactly like that, only reversed: it's not the supposedly harmful thing that we are taking out of something enjoyable but problematic, it's the opposite: we are taking the supposedly valuable thing out of something that is too perfect to be enjoyable.
Sunbeam City is a Libertarian Socialist solarpunk instance. It is ran democratically by a cooperative of like-minded individuals.