Force lightning almost always required a living conduit for the energy to be channeled; thus Darth Vader, despite being an immensely powerful Sith Lord, was never able to properly employ this ability, as any attempt to generate it carried the risk of shorting out his life support systems.
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.
Sith specifically channel Force lightning using their hands. Seemingly, because Vader's hands are no longer there, he can't channel the dark side of the Force through them, meaning that he can't use Force lightning.
Force lightning can be deflected and absorbed by a lightsaber, and select Jedi have proved able to neutralize the technique through the power of the light side.
Vader has the power and control to theoretically channel lightning away from his circuitry. However, to use it himself, he would have to draw from the Dark Side - that is, his own self-hatred. If Vader were to use a pure manifestation of the Dark Side, his own demons would cause it to rebound upon him.
Vader relies on the complex life support system of his suit to survive and it happens to be very vulnerable to electrical discharges. So, if Vader ever had unleashed Force lightning, there's a good chance it would've caused his suit to short circuit, thus, killing him.
Grandmaster Yoda himself was capable of summoning force lightning in the form of Emerald Lightning. Galen Marek was an extremely skilled user of this Force power, even after his conversion to the light side, rivaling Darth Sidious.
Force lightning, also known as Sith lightning or dark rays, was an offensive power that Force users could conjure through the dark side of the Force.
Jedi DID Wield A Form Of Force Lightning In Legends
It was considered forbidden by the old Jedi Order, although a few masters - such as Plo Koon - studied the technique and even used it on occasion.
Quinlan Vos described the feeling of being struck by Dooku's lightning as both burning and freezing his limbs. Those who were harmed with Force lightning often writhed in pain with uncontrollable muscle spasms.
Gray Jedi commonly demonstrated their skills with both Light and Dark side Force capabilities. For example, the capacity to construct a lightsaber from scratch, along with unique Force talents such as Force lightning.
Through his duels with Darth Sidious and Count Dooku, it was well known that Yoda could absorb and deflect Force lightning with his palms.
Star Wars: The Rise of Skywalker hints at Palpatine's real purpose for Darth Vader. It's an open secret that Palpatine was disappointed with Darth Vader; he thought he was getting the Chosen One, a force of nature who could not be beaten, and yet Darth Vader was defeated the moment he crossed blades with an adult Jedi.
During the Invasion of Mon Cala in 18 BBY, the Sith Lord Darth Vader fought in the Battle of Dac City. In the battle, the Mon Cala planetary defense services fired upon Vader, who used the Force to deflect a blaster bolt.
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.
1 Darth Sidious
There has been no Sith, as powerful, meticulous, nor as evil as the Emperor himself, Darth Sidious. As previously mentioned, Sidious trained in the Dark Side by Darth Plagueis before Sidious killed Plagueis in his sleep, making Sidious a Sith Master.
It's likely Kylo never learned how to summon Force Lightning
From what we learned from the Marvel Comics story on Kylo Ren and his upbringing, along with the information explained and even alluded to in the sequel trilogy — it's entirely likely that Kylo never completely learned how to harness Force lightning.
Why couldn't Maul produce Force Lightning? Because he was weak. “Darth” Maul isn't even a Sith, he's an assassin.
Anakin is supposedly more powerful than other Sith Lords like Dooku yet he can't use force lighting.
The color of the bolt depends on how hot it is; the hotter the lightning, the closer the color will be to the end of the spectrum. The color spectrum in this case start with infared which is red and the coolest up to ultraviolet which appears violet and is the hottest.
Blue or Purple Force Lightning
The most common variation of Force lightning is a blueish-purple color. It was the original version that the Emperor used in Return of the Jedi, and it has continued as the mainstay for most Dark Side users. As such, it has been seen many times on the big screen.
Red Sith Lightning was a variant of Force Lightning most notably used by Darth Anihlus which was crimson red in appearance due to it being pure dark side energy rather than electricity. It was just as if not more damaging than regular lightning.
Originally Answered: How did Rey use force lightning while she is a part of the light side of the force? She's not “part of” the light side. She's a Force-using person who got angry, while using the Force, and had sufficient potential and drive it manifested as one of the nastier versions of Dark Side energy.
In both canon and Legends, Jedi will sometimes use red-bladed lightsabers in emergencies where they're missing their lightsabers and a Sith weapon is the only one available. Some Jedi are explicitly shown using red lightsabers in Legends, however.
Force Lightning Isn't Only For Sith
Chronologically, Count Dooku is the first to use Force lightning in Star Wars: Attack of the Clones. He then goes on to use it extensively all throughout Star Wars: The Clone Wars, with he and Palpatine being the only people seen to use it in the prequels.