Dooku, during his time as a member of the Jedi Order, utilized it spontaneously during a painful Force vision to kill some Presagers of Hakotei, without any known prior training and also used it on Shenda Mol to save his Padawan Qui-Gon Jinn while on Numidian Prime, although Qui-Gon was unaware of it.
Dooku first used Force lightning at a young age. According to the audiobook, Dooku: Jedi Lost, he was once abducted for a Dark Side ritual, conjuring lightning to kill his captors and escape. Dooku went on to become one of the greatest Jedi masters, but his ability to use lightning was seemingly a natural talent.
Some members of the New Jedi Order such as Luke Skywalker (who also used the dark side version at times), Jacen Solo and Jaden Korr also used light side Force lightning known as "Emerald Lightning", or Electric Judgment, but it remained somewhat controversial to some Jedi.
Darth Vader can not use force lighting, because of his severed arms. Robotic hands can't summon the force lighting. However Darth Vader can still use other forms of the force, such as force choke.
Electric Judgment, also known as Emerald Lightning, was a Force power used by the Jedi to spray electric bolts of variable intensity from the hands and fingers.
Anakin Skywalker's Chosen One Potential Was Permanently Stunted. The Darth Vader comic book series reveals that, while the eponymous Sith Lord was indeed capable of using Force Lightning, the electricity could potentially destroy his life-sustaining suit.
During The Rise of Skywalker, Ray accidentally uses Force lightning on the planet Pasana, believing she accidentally killed Chewbacca. While this moment was used to hint at her Palpatine heritage, it also shows that anyone can use the lightning, but only if they channel their anger.
Mace Windu, with his lightsaber combat form Vaapad, could reflect the lightning back to its source with a "superconducting loop". It required tremendous effort on the reflector's part, however, as seen in Windu's battle with Palpatine; Windu was seemingly able to overcome Palpatine's lightning.
This could change over time as Cal succumbs further to the dark side's allure, so his Force Lightning could start off stunning his opponents before inflicting damage, then ultimately being used to kill.
In Canon, this is not really about Darth Sidious who taught Dooku or Maul, Dooku was already able to use Force lightning as a Jedi Master, before even knowing Sidious.
Although, with the battle against Mace Windu in his office, Palpatine's Force-lightning was reflected back and scarred his face, making it wrinkled and appear far older than he already was.
Dooku's vision for the Empire was superior to Palpatine's, as he aimed to transform the Jedi Order into an unstoppable Sith Army. His talents as a Force wielder, though outclassed by Palpatine and Yoda were also top tier, as nearly all Jedi were unable to withstand him.
Either way, while Vader can use most other Force abilities, Force Lightning needs to be channeled, and Vader's limbs are explicitly not connected to the Force. The Star Wars: Episode III - Revenge of the Sith Visual Dictionary confirms Darth Vader cannot use Force Lightning, and even suggests this is the reason why.
Some have even speculated Sith can grow addicted to Force lightning. This naturally explains why Jedi do not generate Force lightning. Jedi seek to master their emotions rather than be mastered by them; Force lightning is therefore forbidden, as it is best understood as a spontaneous outpouring of hatred and rage.
The simplest answer is Electric Judgement, it was a similar technique that was demonstrated by Jedi Master Plo Koon. The jedi were cautious of it as “lightning” had traditionally been associated with the Sith. Yet Master Koon stated that when he had first used and discovered it he had felt no anger.
Snoke was never a Sith, but he was nevertheless an extremely powerful unaffiliated dark side user. Unsurprisingly, Snoke was a talented practitioner of Force lightning, which he used to excruciatingly stun Kylo Ren when the latter lunged at him.
He was fully in control of the fight when he was blasting Luke. Instead of trying to outright kill his enemy, Palpatine just used enough force lightning to torture him for his entertainment. Not only that, but Luke didn't have to endure it for as long as the Sith Lord.
While unleashing the lightning storm, he screams at Vader that it is a Sith's right to revel in the glory of their own strength, and there's nothing that displays the unadulterated, raw power of the Dark Side of the Force than Force Lightning. This explains why Palpatine's default Force-attack is lightning.
Kylo demonstrably couldn't defeat Snoke directly, instead killing his master via deception. Kylo most likely never learned how to conjure Force lightning, which is considered an advanced skill for dark side users.
While many Star Wars fans would consider Yoda and Palpatine to be almost perfect antitheses of one another, it seems that they share a strange connection through Yoda's usage of Force Lightning in The Last Jedi that is eerily similar to something Palpatine did just a few years prior–and that connection goes much deeper ...
Due to Vader's mechanical suit, he cannot interact with lightning under the pain of suffering malfunctions in the vital life support systems he uses. This is a rare problem for him to come up against, due to only other Sith commonly utilizing such a capability.
