Black Holes are a special type of celestial body. They can be used to gain DarkMatter (a rare resource) via DarkReactor. However, all planets orbiting black holes will never be earth-likes, and no solar energy can be generated from solar panels when orbiting black holes.
Along with Neutron Star regions, Black Hole regions are one of the best places to hunt aliens as they have a 35% chance of spawning every 30 minutes in them.