I've brought up Isaac Arthur's channel before, but it looks like he's decided to revamp his Megastructures series (calling it Mega Structures 1.1), and a few days ago he released a new video on Dyson's Spheres. He does refer to some bits in his original series (all still available), but it's not required knowledge for this one as the concepts (Dyson Beams) are fairly self-explanatory.