Yes, you can find specifics per site here: https://www.nps.gov/zion/planyourvisit/watchman-campground.htm

I was in Loop A and had electricity. In recreation.gov it's sometimes easier to see which sites are electric than nps.gov. In some campgrounds in recreation.gov, you have to randomly click on sites to see details.

Loops A and B have electric, the others do not.

Watchman Loops A