Daniel, from RCTESTFLIGHT on YouTube, has a series of videos where he experiments with solar airplanes, which wad really interesting to watch from the standpoint of a RC and electronics hobbyist:
I love that guy's channel. He does some pretty fun and interesting projects. Bonus is when he writes and records one of his songs for whatever he's building.
https://youtube.com/playlist?list=PLXvxJNOIXBsM83XxVG7tDUmql...