In Black Lightnings origin he is a metahuman born with electric powers, but he hides them. I think it's because he can't control them without a special belt he gets later on, when he first becomes a vigilante.  
 
The problem with his character is he's a famous athlete who previously competed in the Olympic Decathlon. Does the fact that he never revealed the fact that he's a metahuman make him a cheater. Even though his energy based powers don't  seem enhance him physically, there is always that question of whether his energy based power gave him that extra kick that made him such a great athlete.  
 
Does that make him a cheater and is this ever resolved in the DC Comics, at least to my satisfaction.  
 
On another note they do do a good job of explaining why Superman doesn't goto the Suicide Slums of Metropolis. For those of you who don't know, the major villian who occupies that part of Metropolis uses magic that effects the entire Southside of Metropolis.