I've been finding a few coins that deal with solar energy. I believe the biggest one may big SolarCoin. I want to do a bit more research before I invest in them, but this certainly helped! There was another coin I found pretty interesting, which is Geocoin. For some reason the idea of using blockchain for geocache purposes is like the coolest idea ever to me. I could see it picking up a decent following. Thanks for the post! It was a good read :)