Why is electricity the go-to power set for Black superheroes?

In the late 70s, Black superheroes were few and far between, but by the 90s, Black characters became a fixture in comics. Off the top of my head, you had: Icon, Chapel, Spawn, John Stewart, Luke Cage, Steel, and a host of others. However, despite the increased focus on the diversity of characters' races, one trait in Black superheroes has remained utterly lacking in diversity. I'm, of course, talking about the absurd number of Black heroes with electricity as a power set. 

Again, just off the top of my head, you've got: Storm, Static, Black Lighting, Black Vulcan, and even the new race-swapped Lightning Lad from the Legion of Superheroes, to name a few. As a Black comic fan, I always found the preponderance of Black characters with lighting abilities a little odd. Thankfully, Mixed Up Media's YouTube channel found it equally strange and dedicated an entire video to the formulaic trope.