Hydrogen was an element that could be produced from water. The natives of the oceanic planet Kamino generated power for their cities by putting hydrogen taken directly from the abundant seawater in fusion generators.
- The High Republic: Into the Dark (Mentioned only)
- The High Republic: Into the Dark audiobook (Mentioned only)
- Star Wars: Absolutely Everything You Need to Know (First mentioned)
- Star Wars: Complete Locations
- Star Wars: Absolutely Everything You Need to Know, Updated and Expanded
- Star Wars: Alien Archive