Energizer
The energizers or energizing circuits were important -generation components on  starships. If the energizers were out due to damage from weapons fired by a foe, the ship resorted to auxiliary power for powering the ship. In that situation, the ship had limited use of its phasers and transporter.

Energizers could be used for the purpose of re-amplifying dilithium crystals that had been drained by overexertion of ship's systems. The  was forced to do this in 2267, after an encounter with a powerful and disruptive cosmic phenomenon. Captain James T. Kirk ordered Lieutenant Charlene Masters to begin re-amplification immediately, but as she was in the midst of doing so, the crystals were stolen by Lazarus, an unstable individual whom the crew had discovered on the surface of a barren planet. ()

Later that year, while the Enterprise was engaging in battle with an extremely powerful planet-destroying weapon, deck seven reported a power failure in the main energizers, necessitating the implementation of emergency procedures. ()

In 2285, Commander Montgomery Scott was forced to bypass the Enterprises main energizers after they were severely damaged in battle with the , which was under the command of Khan Noonien Singh. ()
Energy technology