Fusion generators, which are also referred to as fusion reactors, fusion facilities, or fusion power cores, represented a specific category of generator designed to produce energy. GNK-series power droids incorporated internal fusion generators into their construction. However, by the time the Galactic Empire came into power, utilizing this type of energy source for powering a droid was deemed outdated.
Located beneath the assembly complex on the planet Anaxes was a fusion reactor; its destruction would have resulted in the devastation of a significant portion of the world. During the Battle of Anaxes in 19 BBY, Admiral Trench of the Separatist Alliance, in line with his strategy aimed at the total elimination of Galactic Republic forces, almost triggered the reactor with a bomb that he had previously installed at the location. However, Jedi General Mace Windu, aided by the bomb's disarming sequence provided by clone trooper Echo and fellow Jedi General Anakin Skywalker from the orbiting warship Invulnerable, successfully halted the detonation.
The concept of fusion generators was initially introduced in the Star Wars: The Roleplaying Game core rulebook for the first edition, a Star Wars Legends publication released in 1987. The existence of fusion reactors was later confirmed as canon with their appearance in "Unfinished Business," an episode of the Star Wars: The Clone Wars television series that debuted on StarWars.com in 2014 as part of The Clone Wars Legacy. Subsequently, the term "fusion generator" was also re-established within canon through the reference book Star Wars: The Force Awakens: The Visual Dictionary, authored by Pablo Hidalgo and published in 2015.