Palpatine (Star Wars) is a master at generating Force lightning.
Garnet (Steven Universe) generating electricity to charge a car battery.
Zapfish (Splatoon) are used by both the Inklings and the Octarians as a source of renewable power.
The Great Zapfish (Splatoon) generates enough electricity to power the entire city of Inkopolis.
The Flash's (The Flash TV Series) connection to the Speed Force causes his body to generate massive amounts of electricity.
Denki Kaminari (My Hero Academia) possesses the quirk "Electrification", allowing him to generate electricity from his body. However, exceeding his wattage limit would short circuit his brain, leaving him temporarily brain dead for an hour.
Galian's strongest ÄRM, Guardian ÄRM, Torpedine (Marchen Awakens Romance) is said to be able to generate the most deadly lightning.