Started really with Storm in 1975, although, yeah, her powers are weather control, not specifically lightning, but lightning is definitely her power move.

Before Storm, you had Black Panther, Black Goliath, and Luke Cage, not electrical powers.

But AFTER that…

Black Lightning - 1977

Black Lightning is a great character, but Tony Isabella holds the rights to him so it gets complicated doing stuff with the character.

As a result, you get Black Lightning knock offs that can be used without the rights entanglement.

Black Vulcan - 1977 (Super Friends animation)

Static - 1993 (comics), 2000 (animation).